You know the fish that drove my nitrates through the roof? Anthias, my OSFF and seahorses. Preds aren't the automatic bioload people think. They are heavier per inch than a herbivore fish, but there are tonnes of regular fish that are bioload rivals. The tanks where I had problems were tanks that I had to pour food into it and the fish caught some and some blew behinds the rock etc etc. If you pour food in your tank to feed 'whoever", than you will have a messier situation and that is common of a lot of reef fish. I stick feed my preds so there is zero mess. 100% goes in their stomach. I put a trio of blotched anthias in a pred reef and you could see the tank was starting to have some cyano issues and what not. I started stick feeding the anthias and the cyano went away without me stepping up the maintenance.