Really Need Help With Cyano

So I have been battling with cyano for about a month in a 2 and a half year old reef tank. The tank is a 20 gallon long. My cyano is really getting out of control forming 3 inch hairs from the rocks to mainly the sandbed and even the back glass. Its everywhere and it's started to go over coral! I am using rodi water. I have an odysea 4 bulb t5 light. I have a canister filter running carbon and seachem purigen. I feed once a day with brine shrimp. I dont know what to do anymore. For salt I am running red sea coral pro salt. Livestock I have 2 ocelaris clowns. A army of random stuff from reef cleaners (everything is soo small) a 2 head frogspawn. 2 colonies of zoanthids. A large colony of flower corals and a coral that kindof looks like grass (pretty small). What in the world is causing all of this cyano. About 2 weeks ago I peeled most of it out, turned the lights off for 2.5 days and about 95 percent of it was gone. 2 days later its back and its still bad. What is there left to do!
Help!

 

Manual removal, check out your tds on your rodi, pull out any junk building up under your rocks.
Is it the red/maroon kind or the dark brown kind?

 

Tds is 0. Mostly red and brown in the front, the darker kind is in the back.

 

Everything Dingo said, plus check out Dr. Tim's recommendation for slime algae. The stuff works well. Also, more flow!

 

I cant just remove every single little hair of it. So I dont know what to do. I already have good flow.

 

I had this same issue when I changed my 75gal to a 180 gal.
This is what I did
#1 added an extra fan (more flow) this was a big reason it never came back
#2 only feed phyto 1 x a week ( keep feeding low on wasteful frozen foods)
#3 dosed redcyano (cleaned it up in 3 days) never came back
#4 added a carbon/gfo reactor (diy)

I have never seen it again
Sometimes you just have to use redcyano by blue vet to get it out for good - than to keep it out use more flow and gfo/carbon.

what type of sand bed do you have?

 

Try Dr. Tim's combination refresh and waste away regimen in the amounts he recommends. Not knowing how much flow ou have, I won't comment except to say if you have a lot of slime algae there is at least a fair chance more would be appreciated. Regardless. Of what you do with flow though, try the Refresh and Waste Away.

 

its a 20 gallon long with 1050 gph flow rate. Does this sound like a good plan? Manually remove it. Shut lights off for 3 days, then dose it with whatever redslime remover works best. Post which one does for the lowest price. Tell me what you think.

 

All the other stuff is some variant on a bactericide. It will kill it, but it doesn't solve the problem. Use Dr. Tim's. It's a combination of beneficial bacterias. It not only works on the red slime, but you have a much healthier tank as a result.

As for flow, 1050 sounds like a Koralia's, correct? If so, chances are the problem is not so much raw value of flow, it's that it's always on in one strength and one direction such that there are significant dead spots. Waste is accumulating in these. You need more variable flow.

 

Honestly the BEST thing I ever did for my tank aside from the obvious of doing regular water changes and only topping off with R/O water was VINEGAR DOSING!!!

Seriously I had some red slime in my tank that I just couldn't seem to get rid of no matter what I did "it wasn't really bad but it was enough"
By the middle of the 3rd week of dosing vinegar to the tank I had ZERO red slime algae and in 3 months it has NEVER come back, the corals growth and color has exploded and the coralline algae grows like crazy

Check out a few threads about vinegar dosing and give it a shot I really think you will be happy, Normal carbon dosing with vodka according to everything I have read has a tendency to cause red slime to grow even more than it was before, however using vinegar as a carbon source seems to eliminate any traces of red slime

That is coming from personal experience as well as numerous reports from other people