To OP:
Did you pour in the salt then add the water, or did you pour in the water then add the dry salt slowly? Reason im asking is precipitation occurs on reef salt mixes if you add water last instead of first. The reef salt needs to be added slowly a bit at a time in cool unheated water & mixed throughly all the while and afterwards, at least until its crystal clear. Even if its an empty new sys. it still should be mixed this way for clear water & no precip.
Ive never had a new reef water mix that didn't mix up clear quickly but i add my salt slowly & mix it till its clear before adding more. I use IORC.
If you mixed it properly then perhaps that new salt you mentioned may be to blame, bad batch? Do you have any left from the batch to remix & test to see if it goes cloudy or goes clear? Maybe test the new water mix to see if everything is at proper specs per 1/2 cup of mix per gal. at .025 salinity.
What reef salt are you using?
Whatever seems the simplest explanation usually is.
