100%Not true. Corals prefer ammonia but they can use nitrate too by expending a bit of energy. Same goes for algae, plants and some bacteria. Randy wrote explanation about that in his chemistry section.
He won't get rid of them by switching to dosing ammonia.
They do prefer and will use ammonia before nitrate. This was my point I was getting across. Also with the point, if your feeding fish that excrete ammonia why dose nitrate. It's not working, try something else.
I didn't expect the OP to start dosing ammonia. If that's what it sounded like, my apologies.
My biggest point in my text is to try something different because what he's doing is not working.
"The definition of Insanity is doing something over and over and expecting different results."
Albert Einstein