Hello all, Im new to this forum but have been a member of TPT and BCA for quite some time now. Currently I have a 32gal and have been battling Cynobacteria for what seems like forever. I have tried all the old wives tales things that seem to work for everyone else but they are not working for me. Instead of giving up i have become very curious and want to get to the cause of my particular problem. I have tried thus far: blackout with maracyn (did nothing) adding oxygen (made it worse) adding extra flow (made it worse) manual removal (doesnt last long) spot treating with excel (HA! yea right) Constant large WC weekly (nadda) tested my nitrate and it was high so thats when i started doing the major WC. reduced lighting period from 8 hours to 6 and now to 4-5 but have recently moved it back to 6hrs reduced temp from 80F to76F Added fluval lab series opti carb (someone swore to me it worked for her but it does nothing for me) I ended up tearing the whole thing down, washing everything in scalding water, throwing out infested plants and scrubbing the other plants free of cyno as best i could (which looked cyno free to me). And within a week the cyno was back. this is not a new tank. It was mature, the plants were growing really well but i have no idea what hapenned, none. Currently i am dosing NPK (from a bottle) 5mls weekly and trace 5mls weekly I am no longer dosing excel and i am doing WC 50% weekly and cleaning my filter weekly. I have no other algaes that i can see in my tank. I reduced my feeding dramatically to where i almost feel sorry for my fish My bioload includes 2 adult angels 9 harlequin rasboras 7 rummynose tetras 4 ottos 1 german blue ram I am thinking that i may be overstocked but i was told many times previously that my selection was fine which is why i went with that. My expectations for this tank were to have a lush low light low tech tank. My plant selection was as follows: sunset hygro (melted away from cyno), rotalia roundifolia (melted), rotalia indica (melted), java fern and java fern windlov (infested with cyno and my clump has been reduced to only a few roots), stargrass (nearly gone), m. umbrosum (nearly gone), four leaf clover (completely covered with cyno), anubias nana (brown and yellow holes in the leaves but somewhat ok), crypt windetii green, red, bronze (melted), crypt spiralis and balansae (melted), red tiger lotus (shrunk to only a few very tiny leaves), brazilian pennywort (stems coated in cyno), dwarf sag (doing ok but cyno around edges) The cyno is growing in the high flow areas of my tank and against the back and front glass. It comes off in big slimy sheets. It is not however currently growing on the sides of my tank in the lower flow areas. As a test, i moved my infested java fern to the side of my tank and within a few days the cyno retreated. However it is still visible. Im sure its only a matter of time before it takes over again. I dont know what i am doing wrong. I need searious help. Ive exhausted all avenues but i do not want to rip everything apart and start from scratch again. Ive invested way too much money in this tank and have had nightmares to get what i have in that tank. I just want to know what is going on so i can fix it. So is there anyone here with any new ideas i can try? For those curious here is my thread from Plantedtank.net Finally! Take 2 (pg10)!