How many fish of a group should I buy, how many can I put in one tank and how big a tank should they be in are all good questions. In a perfect world we all have unlimited budgets and enough space to add all the aquariums we want. Reality never seems to work that way for me though.
Most of the fish we sell are in the 1-1.5Ē range and they are difficult if not impossible to sex at that size. Buyers tend to think in terms of how many adults will fit into a tank. Unfortunately fish will not all live to adulthood. Most will, but not all. Things happen along the way and fish die unexpectedly, just like people. Therefore when deciding on a group, always buy more than you want to end up with.
The smallest number of adult fish in a group I would want to end up with is 15, regardless of the tank size. This creates a group of enough size to spread the aggression around. You need at least three males in a group that size. To me that means that the minimum group size to get would be 18, possibly 20. It would be even better if you could get 24 to 28 to allow for sexing and culling excess males when they get older. Nature is likely to solve a lot of the culling problem for you as they get sexually active anyway. My suggestion would be to get a group of 24 fish, grow them to at least 2.5Ē and cull them into the ideal group.
The perfect tank size to put them is difficult to answer. I like using 48-inch long tanks (55 or 75 gallon) and 72-inch long (125 or 135 gallon) tanks if I can. I also like the extra height of a 90 or 180 gallon tank. It just looks prettier and does seem to help somewhat, although not critical. The footprint of the tank seems to be more important than the height. The footprint also determines the amount of fish you can put in a tank more so than height. I must admit to having success using tall and wide three-foot tanks such as a 65 gallon with breeding heavy female groups. You are limited to about 15-18 adults in a setup like that. I donít like using 30-gallon long tanks to keep adult Tropheus as there just does not seem to be enough room to escape an aggressive fish in that tank size.
Regardless of tank size, filtration will always limit the amount of fish. If you canít filter enough waste the fish will always die down to a certain number in the tank. I believe in overfiltering a tank and frequent water changes to keep the water as clean as possible. I have put 50 or more adults in a six-foot tank and over 30 in a four-foot tank with no problems. Crowding the fish tends to lessen the aggression, but it comes with a price. The fish get distracted during the breeding process because of all the other fish in the tank. A second male will come by and break up the breeding routine. You will still have breeding activity, but you will end up with smaller broods per fish.
Ideally, I like to use a 48 inch tank or larger. I try to keep 24-28 adults in a 75 and in the low to mid 40ís in a 135. As I mentioned earlier, I keep about 15 in a 65.
Finally, please remember that this is not scientific; I am only passing along what has worked for me and for others I have spoken with. I donít guarantee any of the ideas in this article will work, but they have for others and me. We are not scientists and this is not a perfect world, so we canít always get it right. These fish are living beings so they will do funny things occasionally.
I hope you have enjoyed reading my ideas. Happy Tropheus keeping! □