sammy boy

freshwaterguy

taken straight from the Wiki - and I'd go along withe the below hope this helps.

An adult rainbow shark thrives in a 55-gallon sized tank with water at the neutral pH range (6.5 to 7.0 pH), with temperature kept between 22 to 26°C (72 to 82°F), and water hardness maintained at 2 to 15 dH. A single rainbow shark is normally mixed with other community fish of similar size.

Rainbow Sharks can grow to 6" 15cm, a 29 gallon would be a start but a 40 or 50 would be much better, bigger tanks give more stocking options and are more stable.

Compatibility
Rainbow sharks are compatible with barbs and rainbow fish, which are upper-tank and middle-tank dwellers. They can also live with danios, loaches, plecos and gouramis. Also they can live with Bala sharks.

Diet
Rainbow sharks are non-picky herbivorous and omnivorous eaters but are primarily consumers of algae in the form of tablets, wafers and flakes. They also eat livefood such as insect larvae, Tubifex worms, periphyton, crustaceans, phytoplankton, zooplankton and aquatic insects. Diet also include lettuce and spinach.

Shawnie

Hi sammy...great advice above but most im portant is the cycle of your tank..read this link for any fish and especially now that you have fish in your tank you are going to have to do a cycle with fish.... http://www.fishlore.com/NitrogenCycle.htm
its alot of reading but something that must be done to have any kinds of fish in your tank...goodluck!