I'm am ex zeovit user. I've had one successful zeovit tank which was amazing, but I moved and restarted. The second tank got dinoflagellates and cyano which made me quit zeovit. I'm starting again with just strong lighting, skimming, lots of LR, and GAC in a reactor. I believe my last zeo tank failed due to dosing bacteria and a carbon source. My PO4 never fell below 0.06, but NO3 was 0 ( by test kits ). I constantly reached out to other zeovit users who advised me just to limit my carbon source and eventually everything would balance out. I've found that some AF users are not dosing bacteria or a carbon source, but just using the supplements, zeo mix, and PO4 remover. This method I like but curious if this is really an option. I don't keep lots of fish so my bioload is usually pretty low. Any suggestions?