I mix up a gallon with distilled water and use that for my spray bottle but the bucket stuff I use regular tap water and don't worry about the cloudiness. I've tested a batch 4 weeks later and it was still under 3.0. For the bucket, I typically on mix up a half batch (2.5 gallons) for sanitizing carboys, kegs, transfer equipment, etc.
It takes me forever to go through a bottle of star san, brewing 15-20 batches per year.