how to get rid of this cyanobacteria?


New member
I have this cyano in the tank and it seems to like very strong flow. I start notice it about 2 months ago. It grows directly in front of a powerhead. So far it has not invade any corals. My parameters:
Nitrate: <0.1ppm
phosphate: undetected
alk: ~11-12 dkh
ca: 410ppm

tested with seachem test kits.

I have 2 types of caulerpa in the fuge below the tank on 24/7 light but they seems to barely survive after 1 year in the tank (tank is 1 year old).



New member
Try to adjust your light cycle, turn lights off for an hour in the middle of the afternoon for a week then after that back on. then off at 3pm for an hour then back on. messing with the normal photo period helped my tank.


New member
best way to fight cyano, more flow, less light time, less feading, remove as much as possible with water changes. if that doesnt work, cyano remover


Premium Member
cyano is a slimey brown ooze with bubbles. That looks like a hair algae with a little cyano also. While there are many treatments to the sympton I would look at the root cause. I think the nutrient level may be the culprit.

Nutrients in must equal nutrients out. Light, food, heat, etc are all nutrients. You must have a way to export them out - animal growth, skimmer, mechanical filter, bacteria (convert to gases), manual harvesting, water changes, etc.


New member
Maybe turn off your lights for 3 days and see what happens.

People have reported good things when they gave this a try.

I never did it but its sounds good.


New member
I had a cyano problem for a while and what worked for me was what has been said above, a coupe days lights off, improved flow, I skimmed wet for a while, and I cut down feeding to every other day. Also I added a couple hermits as I think they do a good job of getting detritus that others cant get. Also keep in mind that when you test your phosphates and nitrates might not register all that high, and that is because the algae and cyano are using up these nutrients.


New member
you're right. I think there are 2 different types of 'thing' growing next to each other. Although now I am confused if they are cyano or algae.
I took a sample of each here