u mike

Mag is a little low. (most people try to keep it up 1300, but for a softie tank, its probably not as big of a deal)
Alk.... (WOW) it should be 7-11 DKH
Alk is probably your problem.
Have you done a water change lately? Some salts randomly have low values in some areas. Double check this reading, and if its that low, you should dose slowly over a few days to bring it up. (i think 1-2 DKH per day is MAX to raise in a parameter.)
If you have done a recent water change, make up a small batch of water and test it. (if its low, then E-mail the company that the salt is made by, and let them know. (theres probably a batch # that they will want to know.))
Some companies will send you a replacement so just throwing that out there.

Double check that your Test Kit is good to.

alk is probably in meq no in dkh format

The higher calcium level is hard on the corals like your mushrooms and zoanthids. Whenever you dose, never pour over your tank. Pour the bottle into a small dosing cup, then hold that over the water. This avoids spills. Same with fishfood. You don't want to bump a bottle into your tank.

I would suggest you bring everything up to these levels:

Salinity: 1.026sg
Alkalinity: 8 dKH or 2.86 meg/L
Calcium: 425ppm
Magnesium: 1350ppm

If you get those numbers, pH will probably rise a little higher.

To get a good start on these numbers, mix up a batch of saltwater and measure it first. Let it mix for a few hours (or for a day), then test everything. If you do a few big water changes, the aquarium will quickly get back on track if your salt mix is a good balance of these numbers.

I'll second everything melev said. And add that my softies seem to do better when my Alk is 9.0 to 10.0 dKh.