Discus.... mom wants them i do not know anything about them.

id say 55g is the smallest tank you can put them in. get 5 for a proper size school. pH gH kH dont really matter if they arent wild discus. just acclimate them the right way. its better to have them in a barebottom tank if they are young. do 20-50% water change daily for young discus.

I grew my 5 out in a 30 gal. Its too cramp, and you have the possibility of stunting your fish. I have to get rid of 3 now. Go for the bigger 55 gal. tank. 20% daily isn't good enough. Bigger water changes less frequently are better. I do 50%+ PWCs every 2 days now. I have 25 gal. garbage bin that I acclimate water in before it goes into the discus tank. It is fairly important that the water that goes into the discus tank during PWCs is within the same params. by +/-1, temp, pH. I never paid much attention to hardness.

get the 55 or bigger..discus are not difficult to raise but you need to give them the best opportunity to get fish that fit the description.

barebottom until they get large...young discus need 3-4 feedings daily and the tank needs to get cleaned as soon as they have finished eating..siphon out any uneaten food.

daily water changes are best for young discus..but you can stretch that out a bit to 3 -4 times weekly..just do larger changes.
discus breeders use thier own formula for food..but you can raise them with over the counter food..mine love tetra colorbits..mix in some brine shrimp, mysis shrimp and bloodworms.

get the fish from a discus breeder..most LFS do not have the same quality as the breeder and the breeders fish will most likely be much healthier and have a higher survival rate.

a 29 gallon is to small for discus. not only can the reach 8 inches long, but they really should be kept larger groups to help them feel more secure and to distribute any aggression (they ARE cichlids).

Discus are schooling fish and since they have the potential to grow to the size of a small dinnerplate a larger aquarium will be required. The bare minimum for discus is 45 gallons with bigger being the better option. Discus require temps. in the tank to be between 82-86 degrees on the farenheight scale with the higher end of that being more preferable. They also require very clean pristine water. If you have juvie discus a bare bottom tank is recommended since they need to be fed several times a day and the bare bottom tank makes the clean up that much easier. They also require almost daily water changes of 50% or more. If you have sub-adult or adult discus you can have substrate in the aquarium or even a planted aquarium and they are fine with it. Water changes can be streached to 2-3 times a week of 50%. (If you want plants in with the juvies you can try putting some plants in terra cotta pots and placing them in the aquarium. Then you can just move them around during the frequent cleanings.) They can be finniky eaters and may not eat right away. Mine would not eat for the first two weeks but now they will eat anything I give them. Try to get the discus from a breeder since the quality of the discus will be better and they will have been cared for better. Also make sure that you intoduce all of the discus at the same time. Since they are in the cichlid family they will establish a pecking order and there will be a dominent discus in any and all setups no matter how large the aquarium may be.

They are beautiful fish and once they are acclimated into thier new home they will give you years of enjoyment. Good luck with them.

Marinemom

A rainbow tank is beautiful too and they will appreciate some plants in thier aquarium. There are several varieties to choose from. Just make sure that you choose some of the smaller varieties for that size tank.

Marinemom

Sometimes Discus can be hard keepers, since they like soft acidic water unlike most other fish. Species tanks are your best bet w/ Discus.