hi
you need to cycle your tank first keith, unless you have already done that??
what is cycling your tank
as a guess is it just make sure everything runs and adjusts so water levels are adjusted a guess
also what fish would be recommended as it is only a small tank 2x1x1 ft i have always liked the neon ones as they are bright and seem really active.
i would have liked a clown fish(nemo) but are lead to believe that they are fresh water fish is this also true.
Cycling a tank is basically establishing the bacteria needed to break down fish waste/plant matter... you can either do it by initially introducing a couple of hardy fish (a bit cruel imo) or do a 'fishless cycle - much better - search the forum for 'rdd1952's excellent, easy to follow article. You will also need ammonia, Nitr'I'te, Nitr'A'te and PH test kits...
I guess your tank is around 18 gallons? You could have 10 Neon Tetras in there - if there are no other fish...
Clown fish are Marine - not Freshwater fish...