Reducing photoperiod to help algae outbreak?

[tgunn]

In late January I had an ozone overdose that caused a pretty bad algae outbreak in my tank..

Most of my rocks are covered in thick mats of brown/black algae like this:



I'm guessing this is in response to the ozone dieoff (I can't imagine how much microfaunau, snails, etc all perished).

Anyways, the BIG problem I have is that the algae growing on the rocks and back glass is VERY difficult to remove. I have a hard time removing it with a toothbrush even. The algae gets covered in detritus and debris, which I know makes the problem EVEN WORSE.

I'm growing chaeto in the sump and have bumped up the photoperiod to 20 hours a day.

I'm wondering, how much and for how long can I reduce my photoperiod to help the algae in the tank die back.

Right now I'm running Halides 1:00pm - 8:30pm.
2 x T5 blueplus come on at 9:00 and are off at 9:00pm.
I was thinking of cutting the halides to 1:00pm-6:00pm. Is that too short?

I'd LOVE to pull things apart and fix it now but I'm SWAMPED with work for my Masters degree and I can't do any major maintenance until mid April.


Thanks!
Tyler