Mate, i tell you what i would do...
How many times a day do you feed your fry?
If more than once, i would bring them down, i feed my fry only once aday, i have tried feeding them more than that before and they didnt touch one bit, so it would of just brought my level up if i kept trying to feed them more than once a day, so if you can bring down their feeding regularities to once a day, then you should be able to speed up the reducing water perameters faster...
Now feeding them less i will not deny will slow down the growth of the fry, but what would you prefer, dead fry or slow growing fry, i think my choice would be clear
My question is, how did your water perameters get so high in the first place?