An led stunner can help, but it doesn't take much MH white to overpower a lot of blue (t5 or led). And stunners are pricey. I know what you are going thru. I had MH with t5's and stunner leds and wasn't happy.
A friend got me looking into leds and I tried a Radion. It works great, good PAR and any color you want. But at $750 a pop they were just too expensive for my needs. Then I found new leds from EverGrow in China (only been out for a couple of months) with built in controller/timer and make the tank as white or blue as you want. I just bought 5 of them (3 different models) for my 4 tanks. Great PAR numbers and as much blue or white as I want. And they cost 30-50% of what Radion or AI sell for. I have an IT2040 over my 70g nem tank and it was only $245. The Radion I had didn't cover enough and I would have needed a second one ($1500... yikes). And the EverGrow has slightly better PAR numbers. Reef Breeders is selling them in the States now.