If you add a bag of live sand, your ammonia will spike. Do not do this with livestock in the tank. Do you have any LR
in the tank? If you have LR
, then the levels will drop soon. With respect to feeding your clown, I wouldn't start feeding him every second day. I think you should continue to feed him as you have been so that he is strong enough to fight the ammonia.
If you are worried about your ammonia level, then change the water. The reason that you have ammonia in the water is because the critters can't eat it all. You have an excess. If you remove the excess by doing a water change, the critters will still get what they need, and the fish will be safer.