Algae / Refugium question

[rbickle]

Hey guys,

I've been keeping marine fish for 20 years or so. I currently have a FOWLR tank, 110 gallons with a 29 gallon refugium that I built. 7" felt filter sock at the inlet. I use a couple of current LED light bars on the DT, and an LED grow light int he fuge. I have a large 6" octopus skimmer and an IR sterilizer in the system. A chiller is attached as well. The tank gets water changes with RO water about monthly.

The past year I've been starting to have a real problem with algae. I've always had very good coraline algae growth, but now I've got red algae all over the fuge and the display tank. Also, my cheato in the fuge is diminishing over time. I put a new batch in a few months ago, and it just keeps getting smaller. I have cut back on the lighting times, so the lights only run about 5 hours per day.

I have tested the water, and nitrites and nitrates are low. I did add a phosphate reactor to the fuge with a new bottle of pellets.

I built the fuge about 5 years ago and it still has the same sand I put in it originally. About 3 inches deep over about 2 square feet.

Still having the same problem. Do you all think I should change out the sand? Any other suggestions?

Thanks,
Rick

 

[mcgyvr]

What are your nitrate and phosphate levels? And please post all other known parameter levels..
By red algae do you actually mean/have cyanobacteria (a bacteria not an algae)? pictures would let us identify it for you..

Why are you only running the lights on the chaeto for 5 hours? (or is that not what you meant by that comment)

IF cyano the easiest direction for you seeing as you have a FO tank is to simply turn the lights off for a week or more..
First just siphon out as much as possible on the next water change then turn lights off.. then wait a week or more and it should all be gone..

 

[lapin]

With out knowing your number we are just guessing. My first guess is you have stripped out too many nutrients and now your macro is suffering. The cyano is taking the oppertunity to grow.
" I did add a phosphate reactor to the fuge with a new bottle of pellets"
Was there some reason for adding the reactor?