They do require stability, so your new water needs to be pretty much in line with the water in your tank from an Alka/Ca/Mg perspective. If you are dosing, topping off, and using a consistent salt mix you should be able to do this. The large water changes are your way of excess nutrient export (don't keep the tank "too" clean or your SPS will die from lack of nutrition!).
I've seen people use micro algae scrubbers with great success so I'd look into that too. I tried the Innovative Marine Ghost Skimmer and it just didn't work well. Microbubbles, poor skimmate production, fussy water level requirement, etc.
Throw in a bag of carbon, get some good flow, do regular water changes on top of the dosing/ato and you're golden.