::Sigh:: GHA has me seriously thinking of quitting.

I had a seahare a while back that did wonders, gave him to a friends cause im out of algae. and I always keep a very heavily stocked CUC.

But last year had the same situation that you do, and I was close to breaking down the tank. But I read on here someone had luck with marine algae fix. I dont like to really dose anything but I really do believe it saved me in this hobby. I dosed for 2 weeks and have not touched it or had any issues since. Everyone survived the dosing cept for the algae

You didnt mention what kinds of lights you have or age, and have you done a black out to try to kill it off?

Not sure if i missed it are you doing Water changes? with RO/DI

Im surprised the tangs arent eating it... Mine Love it but last year it was at a point that no one could make a dent in it, Im assuming like you are now.

 

Calcium stays 420
Alk stays 12....I have a calcium reactor.

I have caluerpa in my fuge...i remove some maybe every 3 months or so..give or take..

 

8, 48" T5's they are only a few months old.

I do water changes on a weekly basis now...have been for about 2 months...25G a week. With RODI water, and i change my cartriges as frequently as I should

I have tried a black out...for 3 days...with nothing.

 

Like it or not, you're describing some of the symptoms of bryopsis. It can look a lot like gha, growing in clumps of thin strands. It doesn't always show the feathery appearance. You said it yourself, your an experienced reefer, and you should be able to defeat gha. Bryopsis can be very deceiving.

 

Make yourself a promise

First thing you do is make yourself a promise that you won't quit until you have solved this problem and your tank looks great, that's when you quit if you want to I know you know what your doing so with that check you PH it should be on the high side with all that GHA, bring it down, lower your lighting time lines, your getting a high nutrient load from somewhere find it. It may be building up in your rock scape, check your flow on that.
I know it's a ----- but take a piece out at a time and scrub it off your rock/coral and start doing weekly water changes, grazers will eat new born better than long strings. Last thing this happens sometimes in our hobby and it is not fun at all but i know you can get it back moving forward, and you will be a better Hobbiest for it! Your not alone

 

Try an ATS. That would grow GHA more easily than ur tank and so use the nutrients up that would otherwise cause GHA.
If

 

k+8)

 

It has no leafy-ness to it whatsoever...Ive seen many forms of bryopsis, and none of them ever looked like this...and even if it was bryopsis, I've raised my Mag to levels to high enough to kill that off...and high levels of mag did not effect this hair algae at all....i am an experienced reefer, and I have tried everything i know of under the sun to get rid of it, and nothing has worked thats why its so frustrating.... My system is not some rigged together piece of work...i have everything done right and done top of the line...i just dont know what else to do to combat it

 

You should try an abalone.I have seen these thing eat algae nothing else would touch.

 

Have you tried this?

The Reef Tank Owner's Manual by John Tullock may help you,
Page 111-115 is good reading

Good Luck!!!!