Change in water source - polyps won't open

[dakineacct]

I have a 3 gallon nano running for about 6 months, with some mushrooms, green star polyp, zoas, a couple of small corals and one small damsel. I recently switched from buying pre-mixed salt water from my LFS to making my own with an RODI and Instant Ocean salt. The TDS going into the RODI is 2, and 0 coming out.

I have 3 different colonies of green star polyps, all have been closed for a couple of days since my first water change with salt water I made. I make a 1 gal water change once a week. Parameters as follows:

Ammonia: 0
Nitrite: 0
Nitrate: 0
pH (taken in the evening): 8.4
Calcium: 340
dkH: 9
Phosphate: 0.5
S.G.: 1.025
Temp: 75-78

Don't know where the phosphates are coming from, not sure if that would cause the problem with the GSP. Don't know what brand of salt the LFS uses, I was wondering if a switch in brand of salt would cause the GSP to close. Any ideas?

[BloodyWelsh]

DId you happen to check the parameters of the water from the LFS before putting it into your tank? Or at least, have you noticed any change in your parameters from before mixing your own and afterwards?

[dakineacct]

Originally Posted by BloodyWelsh

DId you happen to check the parameters of the water from the LFS before putting it into your tank? Or at least, have you noticed any change in your parameters from before mixing your own and afterwards?

I tested all parameters of the water I bought from the LFS (with the exception of phosphate and alkalinity) and there has not been a change.