Wouldn't the catfish keep the water turbid even if gypsum or other product is added to the BOW?? I have a friend that has a few hundred bullhead in his 1/3 acre pond, and his pond NEVER gets to even 6" water clarity and retains a tan, clay appearance. The catfish (bullhead) simply work the pond bottom too much to let the clay settle. And if your newly installed aeration is located on the pond bottom, that also contributes to pond water turbidity. You may have difficulties clearing the water even after applying gypsum or lime due to the fish species you have. Others with more "water clearing" experience may have a more optimistic response and suggestions for you.