RE: Hair Algae..again
Here we go again! 
I would recommend switching to a different phosphate product besides the sponge. I have never been a big fan of them. They seem to be more for "little" problems. Phosguard is one option but you may end trading your hair algae problem for diatoms. Diatoms are easier to control in my opinion. The other option is an iron based product like phosban or rowaphos. The down side there is that you may need to add a reactor for it. Just more plumbing and equipment for a tank your size.
Once you get phosphate under control, then get a pretty good sized clean up crew to eliminate the hair algae. Detritivores like hermits or nassarius will cut down on the detritus that I think is a major cause of excess phosphates. Otherwise, it sounds like you are doing a good job.
Gary
125 SPS, 75 gal. LPS/softie reef, 9 gal. Nano