Red slime algae


Premium Member
Ok, so recently I noticed a resurfacing of red algae in my tank..the slimy kind. I have a power compact lighting system, a protein skimmer, and my tank has been set up for about 6 years. This suddenly sprung up in the last month. Maybe I should thoroughly clean out my skimmer? Do water changes every week for a while? Maybe I need to replace my lighting system with new bulbs??(it's been a while). I mean my test kits show no nitrates, ect...but I'm pretty sure the algae feeds off of that so that is deceiving. What are some good products to get rid of this algae temporarily? I will probobly do all of the above..but I just want any help I can get :] thank you


New member
After fooling with a lot of options over the years related to water changes, tank parameters etc..., I finally started using Red Slime Remover and have never looked back.



Premium Member
I would stay away from the red slime treatments. They have been known to crash tanks. Feeding control and other basic maintenance (as you've suggested) are better places to start, in my opinion.


New member
I changed from PC lighting (I got tired of the bulbs breaking!) to Halides recently. I had used PC lights for several years and found that after about nine or ten months I would always start getting some sort of algae outbreak.

Bulbs shift in their color spectrum as they age. Be aware that you can/will also get an algae outbreak when you change to new bulbs if you don't take the time to acclimate the tank.

I tried to make a slow change (short photo period extended by a small amount every few days) when I changed to Halides and I still got an outbreak of algae.

In my experience, aging bulbs are a problem; so is changing to new bulbs. Seems to be the quandary we are in.

(From my limited experience I have concluded that any sudden change is bad.)


Premium Member
I agree with Bertoni. The red slime remover is too risky. I've had bad experiences with this stuff.

You more than likely have cynobacteria. This is caused by excessive nutrients like phosphates and nitrates.

You may want to test for these first to see where your levels are.


New member
It comes down to too much nutrients in the system.
Do all the maintenance things you have been putting off.
Test alk, calcium, magnesium
Do a large water change you have been putting off.
I have run a diatom filter while blowing the silt hidden in system
If the bulbs are old change them.
Clean the skimmer
Is your return pump running a full speed?

Things that can never hurt
More flow in the tank? Hydor Korralia's?
Feed at the end of the day helps.
Feed LESS food and skip a day?
Reduce the lighting. I cut down on the time of the white lights but left the actinic at the same time.


New member
I'd say the age of the PCs. Swap them out and perform a water change every week for a month.

Should solve the problem. I learned the hard way.

In my case, red slime remover ( two types) killed it than it just came right back again.

The Lights...