Red and brown slime

I have an 80 gallon reef which has been set up for almost a year now. It was moved from a 50 gallon which was previously set up for 2 years. For the past few months i have had a lot of red slime that i can't get rid of. The algae problem is the worst on the back glass and definetly on the sand (40 lbs of fine-grain aragonite) but it also gets on the rock (about 60 pounds of it) and the gorgonians (4).
For lighting i have a MH fixture with 2 10,000K bulbs, 10 actinic LED lights, and 4 actinic PC bulbs. I know the LED and PC bulbs are older but i changed out the MH bulbs last August. For filtration there is a corallife super skimmer, a microfilter (mini canister?), aquaclear 110, and 3 powerheads going in opposite directions. There is plently of flow in the tank but the algae won't stay at bay. I literally have to scrub the whole tank twice a week to keep it clean. I have been growing 19 1-foot mangroves in the refugium to keep down nitrates and phosphates. They have been living for about 10 months. Nitrates are at 5 ppm and phosphate is at 0.5 ppm, yet there is still a lot of red slime. I have been dosing with algaefix off and on for a few months.
Also, every night the red slime on the sand dies, and then comes back the next day..
What can i do about this problem?

 

How old are your bulbs? What is your water source?

Does the canister get cleaned routinely?

Have your tried any GFO or phosban?

 

It is cyanobacteria. You will need to get your PO4 down to around .03ppm. Siphon out the stuff whenever you see it and siphon the sand when you see it on it.

You are going to need at least 1 mangrove per gallon of water to have a chance of removing the P and NO3 naturally.

Using GFO in a reactor will help a lot. An algae scrubber will work very well too.

 

MH bulbs are 11 months old. Actinic LEDs and PCs are 2+ years old.
Since my dad threw out my RO unit, i have been using dechlorinated tap water. Sink water tested to be the lowest in phosphate so i use that. I have not used any significant amount of RO water in 9 months.
What is GFO? and no i havent used phosban.

 

GFO Granulated Ferric Oxide.

 

Granular Ferric Oxide/phosban same product really, binds up the phosphates.

Any convenience store or walmart carries RO/DI water.

 

Have never seen RO/DI water carried at any Wal-Mart or convenience store?? Really??

 

Yeah: It will say filtered by use of reverse osmosis and deionization. Or one or the the other. They also have water stores here where you can get pretty decent water for 25 cents a gallon. I would however not use the water machines found outside of stores that say UV filtered and such as I am of the mind that those filters never ever get changed.

 

Algae problems are usually caused by aquarium water with excess nutrients like phosphate, nitrates etc. You can try and siphon out what you can to remove the algae in the short term. In the long term you may have to examine how you care for your tank. There are some commercial dry foods also contain excess nutrients and other undesirable things like nitrates, phosphates etc so I strain/rinse my fresh/frozen foods before feeding my tank. You may want to consider feeding your fish less often. Also, changing your photo period, light bulbs more flow, using RO/DI water and a high quality salt with little if any NO3, phosphates etc like Tropic Marin may help too. Adding a phosphate remover and increasing flow in your tank may help too.