My oscar seems to lie on the bottom of the tank sulkimg at me, why is this?? prams are spot on, no ammonia, nitrite, and under 20ppm nitrate (think thats the right way around lol) and ph at 7.5....only tank mates are in my sig...what is wrong with the fella? eats spot on when ever i feed him...and has turned reallllly pale (i think this is from the light sand i added the other week and no black back ground any more...he has been doing this for a couple of days...thanks