Hey Mollydog - you have extra nutrients coming from somewhere, or they are accumulated in your rock. Some suggestions to try, in this order.
1) re-position the powerheads and turn them up for a few days - try to see if there are pockets of detritus collecting somewhere. Lift up your rocks if you can - detritus tend to collect around the bases.
2) Clean your skimmer and make sure it is running effectively. Tune your skimmer to skim slightly more wet for a week or two, but make sure to watch top-off and salinity.
3) If you have only two small fish and a few cleanup crew, it is not your bioload, but - be aware of how much you are feeding.
4) check your RODI filters - i.e. look at your TDS values leaving unit, and test your output water for nitrate and phosphate.
5) Clean your sponges, or better yet remove them. Clean your filter sock (every 2 days for the next couple weeks) Suck out any detritus in your sump
6) Do another round of manual algae removal - but, this time turn up pumps and add a filter sock to your sump input to catch and remove all the stray bits of algae. What can happen is these stray bits of algea settle, die, decay and put back into the water all the nitrate and phosphate that were once in their structures - this just starts the cycle again, making more algae grow. Then do another water change.
7) If you have no corals, reduce your photoperiod
8) Add a GFO reactor
9) Check your lights - if you are not running LED's, other types of bulbs you have may be old, their spectrum shifted, and contributing to the algae.
Probably not a good idea to start carbon dosing (vodka), until you solve your nutrient issue. Carbon dosing is much more effective at keeping already low nutrient levels there, rather than bringing down very high levels, and there are risks with dosing into a high nutrient tank. And, we still need to find out where your nutrients are coming from. Lets try the above measures, and see what happens. Hair algae is completely maddening, but - you WILL conquer it. It will take some time, just stick with it.