I meant a nitrate PRODUCING factory, that is out of control, and contaminating the water columnI hear the term nitrate factories in the reefing forums. As one experience reefer said, this is a misnomer as that is what you want with a biological filter, complete the nitrogen cycle which converts organic material to nitrates. If you don't want a nitrate factory, use a protein skimmer which removes the organic material before it breaks down into ammonia.
Without proper cleaning, wouldn't all gravel beds would become a nitrate factory?