Tall Tank purchase

Question
I am looking to purchase a new tank.  I consulted the Wet Web Media about this issue, but want a second opinion.  I use to keep fish, having a 55 gal and 29 gal tank.  I miss them and want to get back into fish keeping.  I've kept Cichlids, Goldfish, all kinds and know about the different varieties and their needs.  With that being said, I found a very cool tank at our local aquarium that is approximately 18"L and 17"W and I think 22"H.  I can't remember the exact height, but it is basically a 37 gallon TALL tank.  I've read about goldfish and cichlids and their need for a longer tank with open space, and easy access to the top for oxygen etc.  Something about gas toxicity has been said about tall tanks.  I don't want to have a hard time keeping fish.  Is the TALL tank an issue with fish keeping?  Are there certain, recommended fish for this tank?  I don't want unhappy or dead fish, for sure.  ANY information, the more the better, you can provide me would be m!
ost helpful and very much appreciated.

Answer
Hi Anne,

Wet Web Media knows their stuff - when I don't know the answer to a question, I refer folks to them! An answer from Neale Monks is especially helpful, since he takes time to explain everything thoroughly - even if it has been said before on the FAQ pages.

Basically, it's "floor space" that counts in an aquarium. The profile, not the height, determines the amount of surface area there is; the height serves no other purpose, other than it adds gallonage to the tank, which means there is that much more water diluting the pollution the livestock in your system are producing. In the same way that a sump below the tank or a refugium hanging on the back adds water to the system (it is used as a form of filtration too, but look past that for a moment) having more gallons is helpful in that regard.

As far as toxic gases building up, I don't know about that, it doesn't seem likely to me! Folks spend far too much time concerning themselves that sulfur and other poisonous gases are going to build up in their gravel and kill their fish when this pocket of anaerobic bacteria is disturbed. It's possible, I guess, but not that probable! Ponds have plenty of anaerobic activity going on, have you ever gotten yourself a handful of swamp mud? (I have! Don't ask.) It stinks like rotten eggs.

All I can say about that is, if you use sand - get some Malaysian trumpet snails, which will aerate your sand bed much as an earthworm aerates soil. If you use gravel, it will be necessary to siphon it regularly. Once a month is sufficient, no need for any more frequent gravel vacuuming...and many folks get by with less. Weekly water changes are far more important than monthly gravel vacuuming!

Now, I did a calculation using an "aquarium volume converter" and the measurements you've provided equal 29 gallons, not 37 gallons. You said you were not certain about those dimensions, so I'll leave it to you. Just go to Google.com and type: calculate aquarium volume

In any case, I hope those observations answer your question. As far as keeping cichlids or goldfish, it can be done, but you must take care not to overstock. Two goldfish can be kept in a 29 gallon tall tank (which is essentially the same as a 20 gallon long tank, in spite of having almost 50% more volume) so I bet you could get away with three goldfish, as long as they are not comets or shubunkins (which get much too large, more pond fish than ordinary aquarium fish!)

Cichlids...well. If you mean African cichlids, here's the thing: African cichlids are like goldfish in many ways. They need hard and alkaline water and a vegetarian diet. However, almost all African cichlids DIG, and for them to feel comfortable they ought to have lots of caves and rockwork. Since your prospective tank is tall, what would look terrific would be some interlocking rockwork stacked as tall as the height of the tank. However this would have to be done *very* carefully and likely glued together with 100% pure silicone, otherwise they are likely to topple it. Been there, done that!

African cichlids are not an especially fine choice, but other dwarf cichlids might work. Kribensis or jewel cichlids, for example - which incidentally come from Africa, but are more like South American cichlids in their behavior. Another dwarf cichlid to try would be Bolivian rams, much hardier than blue rams. Almost all of these (with the possible exception of jewel cichlids) could be kept with other community fish such as tetras, rasboras, etc. Just avoid fish like giant danios and red eye tetras, these are fish who do best in long tanks, since about all they do is go back and forth all day long.

I do hope that helps, take care!
Nicole