[mcgyvr]

Thats expected when you start vacuuming/disturbing a sandbed..
Its a diatom growth fueled by excess silicates likely..
It will pass as those are consumed by the diatoms..

The phosbond should help there too as that can also remove silicates but I recommend removing it after as your phosphate levels don't indicate a need run it..

sand bed vacuuming is a "do it all the time or never do it" kind of thing..
Personally I recommend people never disturb the sandbed and instead put some critters into the tank to keep it healthy.. nassarius snails/bristleworms/cucumbers/sand sifting fish,etc...