Sketchy fish assortment?

Question
QUESTION: Right now, I have a 45g with an odd assortment of fish.

I have four angel fish, 2 rainbow sharks, 2 bala sharks, and 2 blackfin sharks.  10 total.

I understand the balas can grow quite large, almost 2 feet or so in a proper sized tank.

I also understand some of these are 'schoolastic' and might not be very happy with only 2.

They've been fine for a good while now.  What are the long term projections of the tank as these fish grow?  Will the size of their tank limit their growth accordingly?  Will they die off a little at a time over the course of months?

Our dentist has a large, octoganal tank with a massive bala, an oscar, and other large ciclid (red devil?).  They've had it for years.  They never have problems and the fish coexist even without schools and with agressive fish in the tank as well.  How?  Once fish are that size, do the rules change?

ANSWER: Hello!

They will not live long. A tank with that stocking should be a couple hundred gallons, and eventually you may end up with just one or two fish. The rainbows are good though.

Your dentist may be lucky, sometimes fish can live in small tanks, not always but sometimes they find a way to live in very very poor conditions. But you can be certain that those fish are not happy, and will not live a full lifespan. It will be cut off a few years. Also, when a tank is overstocked and the fish are unhealthy there are usually now agression issues. Agression can be a good sign.

As for schooling, balas technically are cyprinids (in the minnow family), and do better in schools, as well as the black fins, which are technically catfish and can also go in schools. However, I think a fish would rather be alone in a clean, not crowded tank than in a overstocked, dirty tanks with 10 other fish. If you have the room it is a good idea though.

-Nick

---------- FOLLOW-UP ----------

QUESTION: Thank you much.

I think its a bit decieving, how the pet stores have dozens of angels in a tank, or dozens of balas or even mixed combinations at that size.  And the people who work at those stores dont give you much insight or say "Hey, those get huge, they need a massive tank to live in"

But of course, they do want to sell fish =)  Would think they'd audit someone from the start.

10 fishes does not seem a lot for a 2' x 2' x 2' tank of that size but once adults I could see where issues arise.

As they grow, getting a second tank could be an option yes?  I know the angels can get up to 6" or so as well as the rainbow sharks.  How much is too much?

Answer
What do you mean by how much is too much? As in tank size?

Well that all depends on who you are personally. Ideally you should get a 250 gallon tank. But when you get to that size it is more than just throwing a filter and a heater in and calling it good.

You'll need a sump (you can use your old tank for that), maybe a wet/dry filter or an FX5, and you could throw the assortment of heaters in the sump.

With tanks of that size, you need to watch your floor doesn't callapse.

With all the decor and water and such, 1 gallon weighs about 20 pounds. Your tank would weight about 5000 pounds, larger than most cars.

Also, angels and black fins are not really supposed to be mixed together, and there will be problems as they arise. I recommend taking the larger fish back to the store, you could add some more angels and smaller catfish instead.

Do some research, join a fish forum (like the one below for example), and talk to others. Everyone has different advice they can give you, and you will learn a lot.

Also, there's a buddy of mine who is also on AllExperts. He is only in the saltwater fish section and his name is tyler. Ask him a question about setting up bigger tanks if you would like, he may not mind getting a good FW question if you ask nicely. He has more experience in bigger tanks than I do.

-Nick