Considerations for Buying a Large Tank
by Rex Niedermeyer
First published by The Saltwater Enthusiasts Association of the Bay Area (SEABay)
Aquarticles
Some of the things I would think about before choosing a large tank are the following:
1. Power access
A large reef tank requires a lot of power unless you use natural lighting, and even then
it can be substantial. My 240 gal. reef uses close to 30 amps peak, which means that you
will need at least two dedicated breaker circuits of at least 15-20 amps each.
Significantly more than 240 gallons and you might need three. Unless you are fortunate in
your current house wiring at the selected location you will likely need to add additional
circuits and wiring to support a much larger tank. Also expect fairly hefty power bills of
between $100-200/month just for the tank.
2. Structural support
Make sure that the location where you plan on placing the tank will support its weight. As
long as the tank is not too deep (greater than 30"), or you don't plan to place the
tank in the middle of the room, you should be OK for loading. If either or both of the
above mentioned conditions are true, then you need to make sure the actual loading (total
tank weight/foot print area) is within your floor's capability (if it is a slab floor then
there should not be a problem).
3. Heating and cooling
Equipment to support a large reef tank can generate a lot of heat (assuming you are using
metal halide lighting). Depending on tank location, cooling, even with a chiller, can be a
problem. If you can remotely locate the chiller outside in a cool location (you do not
want the chillers subjected to full sunlight as they can fail if their ambient temperature
runs much above 90ºF), this can help reduce some of the heating, but between the lighting
and pumps required for a large tank you will still have plenty. If your house is
air-conditioned this will also help, but if not try to have a significant number of fans
strategically placed to help cool the tank through evaporation, as well as your lighting
system set up with a controller that can shut it off if tank temp. gets too high. (I also
have my skimmer pump set to turn off if temp. is too high as the pump for that is fairly
large).
4. Evaporation rate
A large tank evaporates a significant amount of water on a daily basis (likely several
gallons). I would try to have some sort of automated top-off system planned and plumbed
unless you really like having to add this much make-up water to it every day or two.
5. Maintenance
My cardinal rule is that if maintenance is difficult to do, it will not get done,
particularly for a large tank. Make sure that all pumps, outlets, filters, and especially
the sides of the tank that need to be cleaned are readily accessible. I would also make
sure that the tank layout and positioning allows you to reach most any point in the tank
both for maintenance as well as specimen positioning. One of the keys to making the tank
accessible for cleaning, as well as getting to specimens, is to have a canopy or lighting
system that is easily removed, or constructed so as to not hinder access by allowing it to
be opened or hinged in some fashion.
6. Redundancy/safety precautions
Try to have back-up systems wherever possible. The cost and effort put into stocking a
large tank are such that you do not want a single failure in any one piece of equipment to
cause your system to crash. Use multiple pumps from the sump as well as within the tank
itself for circulation. Have multiple heater units. Place the various pumps and heaters,
as well as lighting fixtures, on multiple electrical circuits (you have to for a large
tank anyway), so that if any one circuit trips due to short or other failure mode, not all
the critical equipment will be shut down. Also use multiple GFI circuits where
appropriate, to minimize the chance of electrocuting yourself as well as your tank. The
ultimate in redundancy is to have an auxiliary power unit available to kick-in in case of
power failure (not for the faint of heart or pocket book).
7.Cost
If you can get used stuff it's a lot cheaper, especially the tank itself (check newspapers
as well as some of the online auctions such as E-bay). A 240 gallon tank itself could run
you $600-1000 new depending on the extras wanted (e.g., multiple overflows, black back,
etc.). Expect to pay over $1000 for lighting a 240, likely more for a larger tank. A large
skimmer could cost you $1000 or so when you add the pump costs in as well. The pumps
themselves will likely cost you several hundred dollars depending on how much redundancy
you plan on having. Cabinet costs depend on whether you want stock or custom - if tank is
much larger than 300 gallons you will likely need a custom cabinet unless you are lucky
enough to find a used tank with its own cabinet.
Even the above equipment costs will pale compared to the cost of stocking a large reef
tank with specimens and rock unless you are very patient and willing. Stock with fragments
and then wait for small to become large.
As to selling your old tank - one option would be to donate the tank to SEABay and then
write it off your taxes. (We are a non-profit organization). Unless you find just the
right buyer for your tank it will be difficult to get top dollar, so the net gain for a
donation may be very similar to what you would get for selling it. (Of course you do have
to wait for tax time to get any benefit).
Believe me, I am not trying to scare you off. Large tanks are really neat, but you
should also be aware that they require more thought and planning than a more moderate
sized tank such as the one you currently have. Let me know if you have any further
questions and I will try my best.
rexn@lanminds.com
Note from Aquarticles: The author of this article, Rex Niedermeyer, has also written a major
series of three articles about Aquarium Lighting, which explain in a straightforward
manner the operating principles of the various types of lighting systems, and their
relative advantages. These articles, "Let There Be Light", may be seen at
SEABay's website, www.seabay.org |