red hair algae on one rock

I bought a fire and ice zoa rock from liveaquaria and it came with a patch of red hair algae (quite a while ago) since then the RHA has continued to spread over that single rock with the zoas on it. It isnt anywhere else but i cant get rid of it. When i test my water my nitrates and phosphates seem to be zero using an api test kit. i tried putting the rock in front of a powerhead but it didnt seem to help. Any suggestions?
Also i have API algaefix which i used in my tank once but havn't again because i got more sps. Should i not use this product in my tank or is it okay?
I was thinking about just confining the rock with RHA on it to a bucket or something and dosing the algaefix in there. Bad idea? i dont know what to do

 

There is a possibility that your tests are reading "0" because the nutrients are being taken up by the algae. Could be a low flow area too. How old are your bulbs?

Just some questions to get things started.

 

i actually just got new bulbs. I have a 4 bulb t5. My previous bulbs were about 5 or 6 months old but they came with the fixture and weren't any brand so i thought they could be causing some algae problem. Maybe my new bulbs will solve my problems
It's really a small patch; the rock is only about a 3.5 or 4 inch disk. And i literally put it right in front of a small rio and noticed no reduction in the algae :-/

 

Manually remove it and see if it comes back.

 

i tried pinching it off a while ago the thing is that its grown throughout the zoas so i cant really do that because i pinch the polyps :/ i guess ill try a high flow area again.
No input as far as algaefix? ever used it?

 

Can you post an image please.

Perhaps you can dab it with it hydrogen peroxide and a Q-tip.

Search Brandons hydrogen peroxide thread and algae control.

You would have to remove the rock with the zoanthids from the tank and the algae can not be growing among the zoanthid polyps. You do not want to get the hydrogen peroxide on the zoanthids.

Check it out it may be a way to go.

 

pic of RHA

 

Thank you for the image.

Yes that is not red hair algae, I will look for the ID.

I suggest for now remove the rock and manually scrub what you can off with a tooth brush.

It looks like and sounds like it could be very invasive so I would act aggressively now before it turns into a total nightmare.

Be careful disrupting the zoanthids and wear gloves if you can or wash your hands and rinse the pieces well before putting it back in the display.

 

I've never used it. I won't ever use chemicals in my tank again.

 

Okay ill do that. But i am pretty sure it is RHA; it has just become very dense and the white dots are just pieces of sand. I think there is also a little cyano on there