Turf algae, GSP and Magnesium

Hello everyone, I recently developed some turf (Brown) algae in my 55 gal. I have never had this before. We can save some time not discussing lights and excess nutrients as I am aware of the myriad of factors that could contribute to algae. It seemed to coincide with using Oyster Feast for the Torch coral (especially) but it may be coincidental. I have since (3 days ago) changed my light scheme and gone to; actinic only on first for 1 1/2 hours then daylights come on for 9 hours and actinic for an additional 1 1/2 hours. Also, at the suggestion of LFS buddy, raised the Mag to just over 1500 ppm. The Mag has been there now for a couple of weeks or a bit longer.
Now, there is the background and where things are now. Here are some questions. Can the raised Mag affect the GSP? It seems that when I raised the Mag (slowly of course) and got to the 1500 level the GSP have "reacted" by closing up for a couple of days and when they have re-emerged they are not as "full" and many stay "in". Now, only about 2/3 to 3/4 are out at any given time where as before the colony was thick and full all the time. I have read other posts of people asking about their GSP retracting and I thought it was odd because from the day I put them in they had never retracted during the day, ever. I thought this was normal so to mine all retracted was a shock. You will see in the pic that they are o.k. but not like they were.
The other question is, if the raised Mag will help eradicate the Turf algae, how long does it take? Any other sure fire remedies you have found to get rid of Turf is appreciated.

 

Jed... Do you know WHAT type of brown turf algae it is? That would help determine what if any herbivores eat it... The excessive Mg typically works best vs. bryopsis, never seen it do much versus other algaes... At least with bryopsis the elevated Mg typically starts causing the algae to lose its "feathers" relatively quickly, like a matter of days...

 

No, I don't know what "kind" it is. Should have posted pic with the original thread I guess. Here it is; you can click on the pic and then click again to get a good look.

 

Hard to believe no one has had Turf algae..........What's up?

 

What about the GSP and Mag question?

 

GSP is very finicky.. i have 3 different frags of it.. if you move them.. change flow.. change anything.. they close up for a few days.. happens to me all the time..

 

No one out rhere has dealt with Turf algae?