Getting cyano and new algae under control

DEL 707 · Jan 31, 2026

I have a 56l tank that over a year old now.
For the last couple of months I've been struggling with cyanobacteria. I've been pulling it out manually and also tried Tropic Marin Cyo-Control. Which has helped but not got right of it.
How ever in the last month of so, I've had a new brown fuzzy algae appear. Also the cyano seems to be growing faster.

It's hard to believe I cleaned that powerhead 2 weeks ago, the stuff seems to come back to fast.

I've been testing my nitrates and my phosphate for the last 2 weeks.
Nitrates have been between 10-20ppm and phosphates has been 0.04-0.08ppm.
I had a ICP test at the end of November, unfortunately I didn't get the advanced test by accident.

ICP Analysis - Reef Zlements

For filtration, I have a mix of dry and live rock. I also have a filter running carbon and bio media.

What is this brown fuzzy algae? How do I deal with it?
Should I do another ICP test?
What's a good way of getting rid of the cyano on my sand? I've been using a pipette to try to such it up, but always ending up losing sand in the process.
I'm doing a water change and big clean tomorrow, is there something I can dip my equiptment in to kill this brown fuzz?

I'm hoping to upgrade to a bigger tank in a month or 2, I really want to get this under control.

Isaac Alves · Jan 31, 2026

how old is your system?

Isaac Alves · Jan 31, 2026

oh i see it...over a year old...

Isaac Alves · Jan 31, 2026

Seems like there is an imbalance in your system causing cyanobacteria and algae to compete for territory. Your nutrient levels as you state them seem fine to me.

Do you have enough flow in the tank?
Are you dosing something that the cyano likes?
Is your lighting old?
You could do a lights out for a few days dose some extra bacteria into your system to try and out compete the cyano.
for the algae...do you have a clean up crew?

I'm a bit controversial in my approach but I am not against using chemical treatments like chemiclean to knock back cyano. I would also start dosing beneficial bacteria, or add some live rock, to introduce new strains of bacteria to out compete the remaining cyano and replenish your microbiome.