[M] ReefKeepers FAQ 1.02 1/3
Kevin N. Carpenter
Note: This header is copied into all three parts.
(Well, more or less. Actually, this is a composite document written
by many folks. It contains information each participant felt was
basic information required for anyone considering maintaining a reef
tank. In reality, its turned into abit of a reference document.)
Release 1.02 - September 1st, 1993 (Reorganized, split into 3 pieces)
Release 1.01 - July 1st, 1993 (First Public Release)
Release 1.00 - May 12th, 1993
Copyright 1993, ReefKeepers, All Rights Reserved
ReefKeepers, for purposes of the Copyright, is the group of authors listed at
the end of this 3-part document. Permission is only granted for it to be
copied, in its entirety, for use by any non-profit organization, in either
electronic or hardcopy form. This document may not be published/posted/
uploaded/copied/or in by other method, electronic or physical, be replicated,
without the explicit permission of ALL of the listed contributors.
The authors of this document have kindly spent the time to bring you their
opinions. They are not liable in any form or fashion, nor are their employers,
for how you use this information. Their opinions should not be construed as
fact; don't blame them if your tank has problems.
Basic Sections:
Part 1)
1.0 Water (Filters/Additives/Test Kits)
1.1 Source Water - Normal City water is not good enough.
1.1.1 Background
1.1.2 DI Filters
1.1.3 RO Filters
1.1.4 Comments
1.2 Additives
1.3 Testable Parameters
1.3.1 Alkalinity
1.3.2 pH
1.3.3 NO3
1.3.4 PO4
1.3.5 Specific Gravity
1.4 Changes
2.0 Filtration and Equipment
2.1 Live Rock
2.2 Protein Skimmers
2.3 Carbon (GAC)
2.4 Resins (X-Whatever)
2.5 Mechanical Filters
2.6 Under Gravel Filters (UGF)
2.7 Reverse Flow UGFs (RUGF)
2.8 Trickle Filters
2.9 Algae Scubbers (somewhat long)
3.0 Lights
4.0 Cost Estimates
Part 2)
5.0 Stock
5.1 Common to Scientific Name Cross Reference
5.2 Coral Agression Chart
5.3 Corals [Cnidaria (Anthozoa)]
5.4 Shelled Things
5.5 Algae
5.6 Possible Problems
Part 3)
6.0 General Catalogs
7.0 Questions and Answers
8.0 Book Review
9.0 Useful Tables
10.0 Credits
=================== Beginning of ReefKeepers FAQ Part 1 of 3 ==================
1.0 Water -
1.1 Source Water - Normal City water is not good enough.
1.1.1 Background
US EPA requirements for water quality from municipal sources is
insufficiently pure for proper reef tank usage. For instance, the
EPA standard for Nitrate (as N) is 10.0 mg/l, over twice the recommended
maximum level. Extremely toxic (to inverts) heavy metals, such as copper
are allowed at levels as high as 1 mg/l.
Most public water supplies have contaminates well below the EPA levels,
and some reef tanks have done fine on some public supplies. In general,
however, it is recommended that some form of post processing be performed
to public water before it is introduced into the reef tank.
Although some people have access to distilled, de-ionized, or reverse
osmosis water from public sources, most will use a home sized system
to produce their tank water. The two most common systems used are
de-ionization resins, and reverse osmosis membranes.
1.1.2 DI filters
De-Ionization (DI) units come in two basic varities: Mixed bed
and Seperate bed. In a Seperate bed unit, two chambers are used, one
for anion resins (to filter negatively charged ions), the other for
cation resins (to filter postively charged ions). Mixed bed units
use a single chamber with a mix of anion and cation resins.
DI units are 100% water efficient, with no waste water. They are
typically rated in terms of grains of capacity (a grain is 0.065 grams).
Once the capacity of the unit is reached, it either needs to be replaced,
or recharged (using strong acids and bases). Recharging is normally
only an option for Seperate bed units. A quick check of the local
water quality charts (normally available free from the water supply
company) will reveal the capacity of a given DI unit. For example, if
a unit rated at 1000 grains is purchased, and the local water supply
has a hardness of 123 mg/l (Missouri River, USA), then the unit capacity
is (1000*0.065)/0.123 = 528 liters = 139.5 gallons of purified water.
Water production rates for DI units varies, but is typically around
10-15 gallons/hour.
1.1.3 RO filters
Reverse Osmosis (RO) units are normally based upon one of two
membrane technologies: TFC and CTA. CTA (Cellulose TriAcetate)
based systems are typically cheaper and do not filter as well
(90-95% rejection rates). TFC (Thin Film Composite) based systems
cost more, but have higher pollution rejection rates (95%-98%)
This filters work by forceing water under pressure against the
membrane. The membranes allow the small water molecules to pass
through, rejecting most of the larger contaminates. CTA units are
not recommended for reef tank purposes.
RO units waste a lot of water. The membrane usually has 4-6 times
as much water passing by it as it allows though. Unfortunetly, the
more water wasted, the better the membrane usually is at rejecting
pollutants. Also, higher waste water flows are usually associated
with longer member lifes. What this means in reality is that to produce
50 gallons of purified water, 300 gallons of total water may be required.
Like any filter, RO membranes will eventually clog and need to be
replaced. The membranes themselves are often expensive ($50-$100).
To help lengthen the life of the membrane, pre-filters are often
placed in front of the membrane itself. Commonly, these filters
consist of a micron sediment filter, and a carbon block filter. The
micron filter removes large particles, the carbon filter removes
large organic molecules and some heavy metals. Of course, the use of
pre-filters makes the initial unit more expensive, but should pay
for themselves in longer membrane life.
RO units are rated in terms of Gallons/Day of output, with 10-50
gallon/day units typically available. Note that the waste water
produced by a RO unit is fine for hard-water loving freshwater fish
such as Cichlides. Some route the waste-water to the family garden,
which is another good use for it.
1.1.4 Comments
The ultimate in water purification comes from combining the two
technologies and processing the water from a RO unit though a DI
unit. If a very high grade DI unit is used, water equavilent to
triple distillation purification levels can be achieved. Since the
water entering the DI unit can be 50 times purer than tapwater, the
DI unit can process 50 times as much. This significantly reduces
the replacement/recharging cost of the DI units.
City water is also unstable. Many cities modify their treatment
process several times a year, dramatically changing its suitability
for reef usage. For instance, Portland has great reef water - most,
but not all, of the year.
1.2 Additives
Calcium (Ca) - required, 400-450 ppm
Iodine (I) - enhanced soft coral growth, removed by skimming
Strontium (Sr) - used rapidly by most corals (weekly additions)
Buffers - used to control pH. Desired range is 7-10 dKH Alkalinty.
Alkalinty can be raised by the addition of one of many commercial
buffer compounds. The addition of Kalkwasser (saturated Ca(OH)2
solution - also known as "limewater"), which is often done to
maintain calcium levels, will also raise the alkalinity level.
SeaChem's Marine Buffer, Reef Builder, and Kent's Superbuffer dkH
are popular. The Coralife and Thiel buffer products have had less
favorable reviews.
Iron (Fe) - used by hair and macro algaes.
Copper (Cu) - Used as a medication. DO NOT USE THIS, IN ANY FORM, IN
YOUR REEF TANK. PERIOD!
1.3 Testable Parameters
1.3.1 Alkalinity
Alkalinity is the messure of the buffering capacity of a solution.
That is, it is a messure of the ability of a solution to resist
changing pH when an acid is added to it. Since acids are normally
produced by the bioligical action of the reef tank contents, alkalinty
in a closed system has a natural tendency to go down. Additives are
used to keep it at the proper value.
Alkalinity is messured with one of three units-- 'meq/l'
(milequivelents per liter), 'dKH' (German degress of hardness), or
'ppm CaCO3' (parts per million of Calcium Carbonate). All tests kits
will messure in one of these units although the proper values
appearing in literature can be expressed in any of the units (although
dKH and meq/l are most common). The conversion for the three units
is:
1 meq/l = 2.8 dKH = 50 ppm CaCO3
Alkalinity is roughly equivelent to the concept of 'Carbonate
Hardness'. The 'ppm CaCO3' unit is the concentration of CaCO3 that
would provide the same buffering capacity as the water sample in
question. Calcium content is refered to as 'Calium Hardness' and is
messured either in 'ppm Ca++'(parts per million of the Calcium ion) or
'ppm CaCO3' (parts per million of the equivelent level of Calcium
Carbonate). Since the 'ppm CaCO3' unit can be used to express
alkalinty and also calcium content, the concepts of carbonate hardness
and calcium hardness sometimes get confused. They are not the same
and can vary independently. Separate test kits are used to messure
each although both tests kits may express results in ppm CaCO3.
Recommended values for alkalinity vary depending on who's work you
read. Natural sea-water has an alkalinity of about 2.8 meq/l.
From John Tullock(1991) "The Reef Tank Owner's Manual":
page 46 - Alkalinity range should be 3.5 to 5.0
page 94 - Alkalinity reading of 2.5-5.0 meq/l is proper.
page 188- Alkalinity should be about 3.5 meq/l. (In reference
to maintaining Tridacna Clams.)
Albert Thiel(1989), in "Small Reef Aquarium Basics" recommends 5.35-6.45
meq/l. This is an artificially high level and many reef aquarists do
not believe in such extreme and unnatural levels. Most reef aquarist
recommend that the alkalinity be kept at or above 3.0-3.5meq/l.
Alkalinty can be raised by the addition of one of many commercial
buffer compounds. The addition of Kalkwasser(saturated Ca(OH)2
solution), which is often done to raise calcium levels, will also
raise the alkalinity level.
A proper alkalinity level will allow hard coral and coralline algae to
proper secrete new skeleton. When alkalinty levels drops, the
carbonate ions needed are not available and the process slows or
stops.
The chemistry of how alkality, pH, CO2, carbonante ions, bicarbonate
ions, and other ions interelate is fairly complex and is beyond the
scope and detail of this document.
Some recommended test kits for alkalinity are the Sea-Test kit and the
Lamotte kit. The Sea-Test kit is very inexpensive and is one of the
only Sea-Test kits suitable for reef use. The Sea-Test kit messures
in division of .5meq/l or if the amount of solution is doubled,
25meq/l. The SeaTest kit is a titration in which the acid and
indicator are included in the same reagent. The Lamotte kit is a
little more expensive, though still fairly cheap, and is somewhat more
accurate. The unit of titration is 4 ppm CaCO3 although in practice,
one drop from the titration tube may be up to twice this amount making
the resolution about .15meq/l. The Lamotte kit has a separate
indicator tablet and acid reagent which is a nice feature.
1.3.2 pH - Suggested reef tank range is 8.0 to 8.3. In general, it
should hold it's own unless alkalinity is low. If alkalinity
is OK, but pH is low, there is probably a buildup of organic
acids or a serious lack of gas exchange (low water surface
area to volume ratio).
1.3.3 Nitrate (NO3) - VERY IMPORTANT, 5ppm or less required, less than
.25ppm recommended. Two standards are used: Nitrate (NO3-) and
Nitrate Nitrogen (N); where N * 4.4 = NO3-.
Nitrates themselves may not be a problem, but serve as an easily
tested for indicator of general water quality. Many hard to test
for compounds (like dissolved organics), tend to have levels that
correlate well with Nitrate levels (in typical tanks).
1.3.4 Phosphate (PO4) - used by hair algae, zero is a good goal.
Less than 0.1 ppm. (Tullock 1991)
Less than 0.05 ppm. (Theil 1991)
1.3.5 Specific Gravity - 1.025 recommended for reef tank.
1.4 Changes
"The solution to polution is dilution". Required to correct problems,
minimally (5%/year) when all set up. Some feel that an occassional
water change (about 20% every 1-3 month) is a reasonable safety net
they may help prevent contaminate buildup problems.
2.0 Filtration and Equipment
2.1 Live Rock - cheap rock has low coralline levels, tends to grow hair
algae well. May be suitable for soft-coral only tank. Hair algae
free coralline encrusted live rock (high-quality Florida and/or
pacific (Marshall and Tonga Island) rock) is highly desirable.
"Berlin" style tanks use high-quality live rock (and protein
skimming) as the primary filtration method with great success.
2.2 Protein Skimmer - Required equipment. Don't undersize. Process
1X tank volume per hour of water AND air. Two basic styles of
skimmers exist: Counter-Current Air Driven, and Venturi Driven.
Both styles work fine, Venturi units tend to be smaller, but more
expensive.
Air driven skimmers should use limewood air stones, which will need
to be replaced often. Cheap limewood air stones have a reputation
of needing to be replaced much more often than high quality stones.
Coralife limewood air stones have a good reputation.
Venturi valved skimmers require occasional cleaning of their valve.
Both designs will require tuning. Expect to spend some time over
the first month or so learning how to keep your skimmer tuned.
2.3 Carbon - some debate, most use it at least a few days a month, some
continuously. Many brands have problems with Phosphate leaching.
2.4 X-Nitrate, X-Phosphate, Polyfilters, Chemi-pure, etc. - probably not
needed in establish, balanced, reef. May cause adverse reactions
in some inverts.
2.5 Mechanical filtration - good idea to pre-filter skimmer water. Floss
works fine, is cheap, and disposable. Sponges work well, but require
cleaning twice a week or so. Natural sponges with a medium fine or
fine pore size are recommended.
2.6 Under Gravel Filters (UGF) - Not appropriate for a Reef Tank. Although
they will work for 6 months or so, eventually detritus buildup will
cause a Nitrate problem. Long term, its virtually impossible to
keep Nitrates below about 40ppm - which is way to high for corals.
2.7 Reverse Flow UGF - An attempt to solve the detritus buildup problem
associated with normal flow UGFs. Good idea that doesn't work well
in practice. This system has problems with uneven water flow due to
channeling within the bottom gravel.
2.8 Trickle Filters - Also known as Wet/Dry Filters. An improvement over
UGF and RUGF filters. Nitrates can be kept low (say, around 5ppm)
with adequate water changes. It does not seem to be possible to
keep Nitrates very low (less than 1ppm) if a Trickle Filter is the
sole biological filteration. Those that report less than 1ppm
normaly have adequate live rock, and find that their Nitrates remain
low even (and often get lower) when they remove all the bio-material
from their trickle filters (turning them into plain sumps, useful
for holding carbon and as a water reservoir).
2.9 Algae Scrubber - Summary: the jury is still out. May help, may hurt,
not currently recommended, especially as the sole filter.
Algae Scrubbers
In most healthy natural communities, particularly coral reefs,
dissolved nutrients are scarce. In aquaria, by contrast, nutrients in the
form of dissolved inorganic nitrogen, or DIN, (a collective term for ammonia,
nitrites, and nitrates) accumulate very rapidly as fish and other organisms
excrete these wastes. The most basic problem in any aquarium is limiting the
accumulation of DIN.
In reef aquaria, DIN is consumed by the community of organisms on the
live rock. It is uncertain what relative contribution is made by bacteria
as opposed to algaes, but it is certain that the live rock community as a
whole can remove a substantial amount of DIN from a reef aquarium. In fact,
it is quite possible to run a reef tank with no biological filtration (DIN
consumption) other than that which takes place on the rock. This method is
part of what is now known in the United States as the "Berlin school" of
reefkeeping.
Other schools of thought utilize additional biological filtration in
separate filters. Traditional reef tanks supplement the filtration provided
by the reef (often not acknowledging the role of the reef itself) with
bacteria-based trickle filters. Many readers probably learned this
technique first, as it has been the dominant method in the United States
amateur hobby for some time. Yet another approach uses algaes, which are
also capable of utilizing inorganic nitrogen directly. An algae filter, or
algal scrubber as it is usually called, is simply a biological filter which
utilizes a colony of algae rather than bacteria as consumers of inorganic
nitrogen.
Algal scrubbers are not new; they are discussed in Martin Moe's (1989)
excellent _Marine Aquarium Reference: Systems and Invertebrates_, for
example. However, algae filters have been regarded in the past as too
bulky and inefficient to be the sole filter for a aquarium. The recent
surge of interest in algal scrubbers seems to have been generated by Adey
and Loveland's book _Dynamic Aquaria_ (1991). They discuss both techniques
which allow an algal scrubber to be compact and efficient and also a number
of arguments as to why they are preferable to other filtration methods.
One reason to use an algal scrubber according to Adey and Loveland is
that it mirrors the way DIN is cycled in nature. They claim that perhaps
70-90% of the DIN in reef communities is consumed by algae, rather than by
bacteria. The two methods produce rather different water chemistry; for
example, algae are net producers of oxygen and remove carbon dioxide, while
a bacterial filter consumes oxygen and produces carbon dioxide. They argue
that it should be easier to maintain the type of water chemistry found over
a natural reef by relying on an algal scrubber.
Also, algae remove the nitrogen from the water in order to build
tissue, while filter bacteria simply put it into a less toxic form. The
excess nitrogen can be removed completely by periodic algae harvests,
while dissolved nitrogen in the form of nitrate is not as easy to remove.
Adey and Loveland claim that their methods can bring levels of DIN down to
a few hundredths of a ppm, far below (in their opinion) the levels reachable
with other methods. A related argument in favor of algal scrubbers is that
stability in natural ecosystems seems to come from locking up nutrients in
biomass, not in allowing it to be free in the environment. An algal
scrubber does precisely this, while a bacterial filter converts it to free
nitrate dissolved in the water.
A final reason to use an algal scrubber according to Adey and Loveland
is that many other kinds of filtration (Including protein skimmers) remove
plankton from the water. An algal filter naturally does not do this, and can
actually provide a refuge for some forms of plankton. The importance of
this effect is, however, a matter of some debate.
As compelling as some find the above arguments in theory, there seem
to be serious problems with algal scrubbing in practice. Many attempts by
public aquaria at implementing reef tanks using only algal scrubbing have
been failures. In particular, it seems difficult to find successful long
term success with Scleractinia (stony corals) in such tanks, and those
success stories which can be found are quite difficult to verify and often
contradicted by others.
Various public and private aquaria have used algae scrubber filters on their
reef aquaria, with disasterous results. The microcosm at the Smithsonain
Institution has yet to keep scleractinia alive for more than a year. While
Dr. Adey has stated how well corals grow in this system, those viewing the
system have failed to find these corals. In an interview with Jill Johnson,
one of the techs responsable for the Smithsonian tank, she stated to Frank
M. Greco that frequent collecting trips were needed to keep the system
stocked with live scleractinia. The Pittsburgh AquaZoo also has a "reef" tank
based on Dr. Adeys algal scrubbers. This tank is nothing more than a pile of
rocks covered with filimentous green algae, and the water is QUITE yellow
(as is the Smithsonian tank) from the presence of dissolved organics (ORP
readings have been around 165). As with the Smithsonian tank, scleractinia
do not survive longer than a few months. The same applies to soft corals as
well. When I (Frank M. Greco) saw this tank on May 3, 1993, there were NO
living corals to be found even though a collecting trip to Belize was made
several months earlier, and 81 pieces of living scleractinia were brought
back. There were, however, two piles of dead Atlantic scleractinia: one
right behind the tank, and the other in the greenhouse housing the algal
scrubbers. The Carnige Science Museum (Pittsburgh, Pa) also uses an algal
scrubber system, but with significant modifications. This tank looks the
best of the three. There are several species of hardy scleractinia and soft
corals that are doing quite well. The water is clear (albit cloudy). The
major differences between this system and the other two is the use of
carbon, a small, barely functioning algal scrubber, about 1000 lbs. of
excellent quality live rock (Florida), water changes, and the addition of Sr
and Ca. The last system I know of that uses an algal scrubber is the Great
Barrier Reef Microcosm in Townsville, Australia. As of this writing, the
system is NOT maintaining live scleractinia, and frequent collecting trips
are needed in order to maintain the exhibit. It should also be noted here
that while Dr. Adey has claimed in his book Dynamic Aquaria that corals have
spawned in this system, what he doesn't mention is that the corals which
spawned were collected only months before the known spawning season.
From these few examples, it should be clear that algal scrubbers are NOT to
be used in systems containing live scleractinia.
Possible reasons why algal scrubbers seem to fall short center around
the observation that it seems difficult to control hair algae growth in
scrubbed aquaria. Hobbyists have for many years seen their stony corals
slowly pushed back off of their skeleton and killed by encroaching algaes,
and much effort in the hobby has been devoted to controlling this growth.
Only with strict control of algaes does coral survival seem possible. Most
or all reefs with algal scrubbers seem to have heavy algal growth in the
tank as well, which the experience of the hobby suggests is incompatible
with stony coral survival.
The main method used by hobbyists to restrict algal growth is to
reduce nutrient availability; in fact, the claim that other methods cannot
reach the same low levels of DIN achieved by algal scrubbing is probably
not true. Advanced hobbyists are beginning to use better tests, such as
HACH's low level nitrate test, and are finding that they can achieve
nitrate levels below 0.02 ppm. Berlin methods seem particularly able to
reach these levels, which are comparable to that on natural coral reefs.
If low nutrient levels can be achieved by both methods, then why is
algal growth a much greater problem with scrubber methods? The answer is
not known, but there are two factors which probably contribute.
First, the discussion so far has mentioned only inorganic nitrogen.
Algaes seem to release much of the inorganic nitrogen which they take up
in the form of dissolved organic compounds (DON), which can also be later
utilized by algaes. The very low levels of DIN measured in scrubbed tanks
may mask the very high levels of DON which persist, providing nutrients for
strong algal growth. This is borne out by many reports that the water in
scrubbed tanks often has a pronounced yellow cast, characteristic of
dissolved organic compounds. Since the water over natural reefs is very
low in DON, high levels may be directly harmful to many corals, in addition
to promoting uncontrolled algal growth.
Another possible effect of algal scrubbing is more subtle. Algal
growth is never completely halted in any marine tank, merely reduced to the
point where macro- and micrograzers can keep them in close check. The net
rate of new growth depends not only on the availability of nutrients, but
also on the amount of existing algal growth releasing free-floating cells
into the water to colonize new sites. Even if the rate of growth of
individual algal colonies is equal, a scrubbed tank has a growth of algae
in the scrubber much larger than a reef tank with little algal growth
anywhere in the system. This possibility suggests that the presence of the
scrubber itself and not merely high levels of DON is an obstacle to the
successful long-term maintenance of stony corals.
The weight of evidence at this point seems to be against the use of
algal scrubbing in reef tanks, and the method should be considered to be
highly experimental. Beginners particularly are advised to avoid this
technique until they have considerably more experience with reefkeeping.
The advanced aquarist may well wish to experiment with this interesting
and controversial method, but it would be unwise to risk the lives of an
entire reef tank full of coral. Such experiments should progress slowly,
beginning with the most hardy of inhabitants. Many of the objections
center on stony coral survival, and it is possible that scrubbed tanks
with fish and hardy invertebrates may do quite well.
3.0 Lights
Rough "rule of thumb" is 4 Watts/gallon, successfull tanks using
1.5 - 6 Watts/gallon.
1) Fluorescent fine (some prefer) for shallow (<20") tanks. Use mix
of bulbs (50-50, 03s, etc.)
2) Metal Halide (MH) required for deeper tanks.
3) Mercury Vapor, Halogen, HPS, etc. - avoid, wrong spectral output.
Now in more detail:
For most aquarium lighting applications, the bottom line is getting the
needed amount/spectrum of light at the lowwest cost, within esthetic limits.
Everyone has their own sets of numbers they would plug in here, for now
lets assumme the following for comparison (Many will debate specifics
found below. Feel free to substitute your own numbers, but the methodology
is sound.)
NO lumens per lamp = 2600 (Phillips F40D daylight, initial)
NO watts per lamp = 40 (ditto)
NO cost per lamp = ~$20 (from memory, DLS actinic day)
VHO lumens per lamp = 5940 (Phillips F48T12/D/VHO daylight, initial)
VHO watts per lamp = 110 (ditto)
VHO cost per lamp = ~$30 (ditto)
MH lumens per lamp = 36000 (Philips MH400/U, initial)
MH watts per lamp = 400 (ditto)
MH cost per lamp = ~$70 (from memory, Venture 5200K)
operate lamps 12 hours/day
replace lamps once per year
electricity cost = $.09 / KWH (your mileage may vary)
Annual cost per lumen
cost = ( cost-per-lamp / lumens-per-lamp )
+ ( watts-per-lamp / lumens-per-lamp ) * 12 * 365 * .09 / 1000
NO cost = .0077 + .0061 = .0138 dollars per year per lumen
VHO cost = .0051 + .0073 = .0124 dollars per year per lumen
MH cost = .0019 + .0044 = .0063 dollars per year per lumen
Basically, in fluorescents, the VHO lamps give a higher operating cost
but a lower replacement cost, for the same total amount of light. But
its close, and you should plug in your own numbers to see whats best for
you. If you replace lamps more frequently then VHO is better, if you
pay more for power, NO is better.
There is a greater variety of lamps available for NO than VHO. OTOH, it
seems that NO lamps can be operated at VHO power levels, with a somewhat
shortened lifetime (the higher replacement frequency is offset by lower
lamp cost), so this may not be an issue at all.
The initial installation cost (basically the ballast cost) is higher for
VHO, even in terms of per-lumen, but this is a pretty small part of the
total cost of the lighting system over the years.
NO requires more lamps for a given total light intensity, so you may not
be able to fit an NO system in your hood if you need a lot of light.
MH seems to be a winner in both replacement and operating costs, but there
are a couple caveats here. The math ignores the effect of the ballasts on
power consumption, whereas I've measured fluorescent power consumption as
less than the lamp wattage (even on conventional transformer ballasts) and
MH power consumption as slightly higher than the lamp wattage. The other
caveat is just the EXTREMELY limited choice of spectrums for MH, which is
why few people use MH without any fluorescent.
MH vs fluorescent also gets into the esthetic effect of water surface
ripples causing light ripples on the bottom/inhabitants with MH, with
many appreciating this effect. Note some (eg Julian Sprung) feel the
variation in light intensity is actually important for
some photosynthetic organisms.
Note many are under the impression MH runs hot, whereas fluorescent doesn't.
In reality, the efficiencies are similar, with MH producing slightly LESS
heat than the equivalent fluorescent. The difference is MH dumps all the
heat in a small space, so the temperature rise is greater. But if you want
to try to get rid of the heat, its actually easier to do it if the heat is
concentrated in one spot, since its easier to get rid of a small amount of
very hot air than a very large amount of warm air.
A separate issue, so far only applicable to fluorescent,
is the selection of a conventional ballast vs an electronic one.
There is no doubt, the electronic ones are more expensive to purchase, but
the savings in electricity offset the high initial cost in a year or so.
Also, if heat production is an issue, the electronic ballasts are to be
favored. The Icecap VHO electronic ballast is widely advertised, however its
advertised claims are also frequently questioned. Advance makes a series
of NO electronic ballasts.
There are yet two more issues, for which there are a lot of questions and too
few answers. Specifically, the short term flicker in light intensity, and
radiated electromagnetic fields.
Fluorescent lamps on conventional ballasts flicker at 120 Hz, which is
above the human visual response, so we don't see it (actually, the flicker
is both in intensity and spectrum). But that doesn't mean other creatures
can't see it, or whether they benefit or are disadvantaged by it. Electronic
ballasts cause flicker at ~30 KHz; it is seriously doubtful that any creature
can detect this, so it would appear constant.
The flicker doesn't have to be visible to have an effect: it causes any
movement to appear strobed, and this may affect the feeding efficiency of
visual hunters.
The fields issue is even more obscure. At least many cartilaginous
fish (sharks, rays, etc) are known to be extremely sensitive to electric
fields, and many crustaceans are sensitive to magnetic fields (crabs with
pieces of magnetite in internal sensory organs). Fluorescent lamps, with
the large area they cover, tend to radiate (using the term pretty
loosely) fairly strongly, but MH, and the wiring, and the ballasts can
radiate too. It's unknown on how significant this could
be in an aquarium (but its known sharks preferentially attack undersea
cables because of the fields, so there is at least indirect evidence its
an issue worth some thought).
BTW, a grounding device reduces the level of induced voltages in the
tank, but this is achieved at the expense of increased induced current,
so its effect (if any) may depend on the species. Also, note if you have
a chiller on the tank, it is probably already grounded through the chiller,
and an additional ground in may increase the electric current.
4.0 Cost Estimates
---------------------------Reef-Tank Cost Estimate---------------------------
Here is a rough estimate of what setting up a reef tank may cost. Two
cases are included, a 20g micro-reef and a 70g mini-reef. The
estimates show the min and max for most of the common pieces of
equipment. The estimates assume a standard type of filtration that is
popular today. If a different setup is used, the price could be more
or less. The equipment includes a tank with some sort of syphon/drain
to a sump and then a return pump back to the tank. A protien skimmer
is installed in the sump. This setup is similiar to a typical wet/dry
trickle filter except there is no trickle section with media. This
allows the use of simpler, less-expensive sump although a commercial
W/D without media could be used. A trickle media could be utilized at
greater cost although many reefkeepers think it is unnecessary. Keep
in mind that prices sometimes vary geographically. Also, availability
may vary. For example, reasonable Florida live rock may soon no
longer be available (at least not for $2-4/lb).
The estimates include the cost of the initial set-up. There is also a
section on ongoing costs. The ongoing cost will vary greatly,
especially considering that you will stock your tank gradually. Keep
in mind that you always end up spending more than you think you will.
If you set up a reef, you will end up stopping at the hardware store
and/or aquarium store for timers, extensions cords, GFIs (a must!),
buckets, hoses, and books, don't for forget books. You should read a
few books on reefkeeping before even planning your setup. An extra
hundred bucks or three _is_ going to leak out of your wallet whether
you plan on it or not. Another factor is that more advanced equipment
may translate into less or easier maintenance. You should keep in
mind that if you go with inferior equipment, maintaining the tank will
be more work. More expense will mean more automated equipment and
less work. Also, some varieties of inverts require more exacting
condition, more light, etc. Plan your purchases so that the stock you
buy has a chance of surviving with the equipment you are using. If
you have a bare minimum system, stick hardy items like soft-corals,
polyps, muchrooms, etc. The minimum included is close to rock-bottom
as far as an acceptable systems goes. It assumes that you are DIYing
much of the equipemnt as cheaply as possible. The maximum in the
estimate is in some areas a little extravagant but not unreasonable.
A good system that is not extravagant could be put together for
somewhere in between the two extremes. Perhaps, for 1.25 to 2 times
the minimum, you would have a very nice system. Some areas are easier
to cut-corners on than others and some of the initial cost may be
incremental, like buying test kits as needed. Also, you may have some
of the equipment already from previous set-ups or be buying it used.
Seek out the advice of an experienced reefkeeper when planning and
pricing your system.
-------------------------------Micro-Reef(20g)-------------------------------
Tank $ 20/ 140 Glass/
Acrylic.
Stand 0/ 250 Sturdy piece of furniture/
Fancy acrylic stand.
Lights 100/ 300 DIY 60W flourscent/
70W or 150W MH hood or pendant.
Main Pump 20/ 60 Large powerhead/
Hobby pump.
Sump 10/ 120 A plastic storage container from the
hardware store / A small commecial W/D
without media. (A nice DIY acrylic
sump can be built for about $40.)
Skimmer 60/ 220 DIY skimmer, power head, airpump/
Small commercial venturi unit with
integral pump.
Plumbing 30/ 100 DIY overflow and misc pipes, etc/
Drilled tank or commerical overflow box
plus misc pipes, etc.
Live-Rock 140/ 400 35lb case of Fla rock plus shipping/
30lbs of Pacific rock plus shipping.
Water Treament 100/ 600 DIY mixed-bed DI with carbon prefilter/
TFC RO unit with DI postfilter and
automated top-off.
Test Kits 100/ 500 A SW combo kit plus and Alk and Ca test/
Most of the Lamotte and/or Hach kits
you think you might need.
Salt 10/ 20 One 50g bag, price varies.
Accessories 20/ 200 There are a variety of gadgets you could
get. You might want to start with a
net or two and maybe a pair of tongs.
---- ----
Setup Total $ 610 2910
--------------------------------Mini-Reef(70g)-------------------------------
Tank $ 140/ 350 Glass/
Acrylic.
Stand 100/ 500 Cheap wood or iron stand/
p Fancy acrylic stand.
Lights 200/ 600 DIY 160W floursent/
2x150-175 MH hood (possibly with Actinics).
Main Pump 80/ 140 400-600gph, price varies with brand.
Sump 10/ 200 A plastic storage container from the
hardware store / a commecial W/D
without media. A nice DIY acrylic
sump can be built for about $50.
Skimmer 80/ 450 A DIY skimmer,powerhead,airpump/
A large commercial venturi unit
with a large pump driving it.
Plumbing 50/ 150 DIY overflow and misc pipes, etc/
Drilled tank or commerical overflow box
plus misc pipes, etc.
Live-Rock 460/1200 140lbs Fla rock plus shipping/
110lbs Pacific rock plus shipping.
Water Treament 100/ 600 DIY mixed-bed DI with carbon prefilter/
TFC RO unit with mixed-bed DI
postfilter and automated top-off.
Test Kits 100/ 500 A SW combo kit plus and Alk and Ca test/
Most of the Lamotte and/or Hach kits
you think you might need.
Salt 20/ 40 Two 50g bags, price varies.
Accessories 40/ 500 There are a variety of gadgets you could
get. You might want to start with a
net or two and maybe a pair of tongs.
You could get wave-makers, circulation
pumps and lots of other do-dads.
Chiller 0/ 600 Don't use a chiller, live somewhere cool,
keep the tank in the basement, or an
adaquately air-conditioned room/
A commercial chiller.
---- ----
Setup-Total 1380 5830
--------------------------------Ongoing Costs---------------------------------
Additives- Most reefkeepers believe that some additives are necessary.
At minimum, a buffer compound is needed to maintain the alkalinity.
Also, some Calcium suppliment such as Kalkwasser or CaCl should
be used. A few trace additives like Strontium and Iodine/Iodide
should also be added. The initial supply of these products will
be around $50. The ongoing rate will vary depending on the size
of the tank.
Water Purifier- If you go with a DI system, you will have to replace
and/or recharge resin. An RO system will require periodic
replacement of the membrane. In the long run, maintenance
of the RO is likely cheaper.
Test Kits Reagents- You will need replace reagents for the tests kits.
Also, the minimum given above is may not be adaquate. The
typcial SW combo kits are not of low enough range for reef work.
They will only be of use during the first few weeks of
cycling/curing. That estimate assume that you will acquire
the better tests over time or have access to someone else's
expensive tests should you need to diagnose a problem.
Electricity- You will need it to run the pumps and lights. It won't be
insignificant. Electric costs vary. Check the KW cost
on your electric bill. Add up wattage of all the equipment you
are using, pumps 24hrs/day, lights 12hrs/day. Calculate what
the electricity will cost. Don't forget cooling, in many areas,
you will need either a chiller or will have to air-condition the
room where the reef is kept. The lights will generate heat. At
minimum, your AC bill will also go up accordingly. Electricity
mini-reef system could easily be a couple hundred bucks a year.
Water- In some areas, water is expensive. RO units waste several times
what they produce in water. This could add a little more expense.
Salt- You may want to do water changes in which case you will
eventually need more salt. Some reefkeepers change
as little as 5% a year. Others change up to 10%/week.
It varies with bio-load and the method you are using to run
your tank. Salt is $10-20 for 50g. A median amount of water
changing is probably 5-10%/month.
Lights- Florescent tubes and MH bubls wear out. Florescent tubes
are usually okay for nine months to a year before spectrum
shifts and/output reduced significantly. Some tubes, like
actinics, may need replacement as frequently as every six
months. Replacement MH bulbs is recommended about every one to
two years (depending upon spectral shift and output degradation).
Add up the cost of your tubes and figure in the
replacement cost based on the estimated lifetime.
Stocking- This can really vary. You probably shouldn't have more
than a couple fish in the micro-reef and not more than
a handful in the mini-reef. The typical fish suitable
for a reef will be from $10(small goby or blenny) to
$30(small angel or tang). You could spend $300 on one purple
tang though. Pieces of coral, decorative rocks, giant
clams and other sessile inverts start at around $20 a piece
and go to many hundreds a piece. Snails range from about
$1/each to about $8/each and are recommended for controlling
algae. Other motive inverts likes shrimp range from about
$10 to $30.
You probably should start with the snails as soon as the
live rock is in the tank. You don't have to have any fish
if you don't want any. You don't have to have inverts either
although that is probably why you set up a reef tank. Just
quality live-rock is very of nice to look at but sooner or
later you will likely want something else in your tank. The
invert stocking will be very incremental and should be.
It is not heathly to add a lot of stock at once. You can
spread you stocking over up to several years. You could spend
anywhere from say $100 to $750 on the micro-reef and $200 to
$10,000 on the mini-reef.
=================== End of ReefKeepers FAQ Part 1 of 3 =======================
--
Kevin Carpenter Internet: knc...@nicsn1.monsanto.com
Monsanto Company Fidonet: 1:100/215.0 (home)
St. Louis, Missouri, U.S.A. CompuServe: 71726,2111
Opinions expressed are those of the author, not the company he works for.