Rainbow Fish

[sXeLifer]

Whats the best size of tank for 3 or 4 rainbow fish?

Cheers
Dan

 

[N0body Of The Goat]

Rainbowfish are schoolers by nature, so you really need tank room for a group of six or more.

As to the tank size, well depends entirely on which species you are looking at keeping and their adult size needs to be considered, bearing in mind they are active fish (especially the common larger varieties)...
The smaller rainbows (Gertrude; Forktail Blue Eye; Threadfin etc) could get by in a 2-foot long tank for a group of six with just two males, but a 3-foot would be better and would allow the possibility of a third male (with six or more femlaes).
Mid-sized species like Celebes and Neon Dwarf need at least a 3-foot for a group of six with two males, but a 4-foot would be better, allowing the possibility of a group of nine with three males.
Larger species (Bosemani; Lake Katubu; Red; Madagascan etc) can apparently get by in a 4-foot with a group of six (two males), but personally I think of these 10+cm fish as being almost as active as my Barilius, who use every bit of length in my 5-foot.

Rainbowfish have adapted to a wide range of environments in the wild (temp, pH/ water hardness, current), so its worth researching your ideas first to make sure they fit in with any other fish you have in mind and what your planned water source is like, using the widely considered "rainbowfish bible"
http/rainbowfish.angfaqld.org.au/Contents.htm (website address changed recently to this)

 

[Rogue4Fish]

I'm finding keeping Rainbow fish that they're quite fragile to keep. I've had a few females die on me now for no apparent reason. I don't know if they're getting bullied by the bigger males, but I am keeping a higher female to male ratio.