Green Hair Algae

Robert a moio jr · May 31, 2017

I have a 90 gal reef tank that is been running for 12 years and I can't seem to get rid of this green hair algae. I have taken the rock out and scrubbed it with a brush, but with in a couple of week it comes back. Took a water sample to my local fish store and all my levels are fine. For my filter I am running a refugium. Changing 15 gal of water weekly. What do I do??
Bob.

chris k. · May 31, 2017

I have been using hermit crabs to some success

Waters · May 31, 2017

What do your Nitrates and Phosphates test at? How often and how much are you feeding? What does your CUC look like? I have had good luck using Vibrant and running GFO. Since I have a semi-aggressive reef, I cannot keep a clean up crew.

143MPCo · May 31, 2017

These are just a few things that "I" have done to combat green hair algae, they are as follow...

More frequent water changes
This should be #1... FEED LESS.
Larger than normal water changes (for as long as it takes)
Adding scavenging media like GFO
Bigger CUC (add more to what you currently have, might need to replenish from time to time as things die off)
Changing the intensity of the light cycle (depending on type of coral less light will still allow it to grow (photosynthetic types))
Changing how many hours the lights are on (I find that 8hrs total light is more than enough, corals in the ocean never get 100%, 100% of the time so why should your tank be any different)
Adding an algae turf scrubber (give it some other place to grow with intense light to out compete for the growth in the DT)
Set your skimmer to pull wet more than dry (if you have one)

Sometimes water testing can be misleading as your parameters might be perfectly fine but it's a clear indication that the green hair algae are consuming whatever it can inorder to grow... hence, your test come back within acceptable levels.

Add this just for conversation sakes...

rich nyc · May 31, 2017

my lawnmower blenny is useless. I like him but he would rather eat myasis than algae.

leepink23 · May 31, 2017

I have battled gha as well, in addition to how much you feed, what you feed is very important. I use to give flakes all the time and now mainly only feed with LRS frozen food.