Corals acting weird but Parameters are fine?

I have star polyps, button polyps, mushrooms and zoanthids. 33 gallon tank, 2 clowns, 1 cleaner wrasse, 1 firefish, 5 reef safe hermits, 8 margarita snails. This morning the corals were all fine. They were all open and happy. i went to the fair that was in town and was gone about 2 hours and when I got back my stars were ALL closed, my buttons were all closed and kind of collapsed a little. My zoas are kind of open but with every minute that passes they are closing up tight, but the mushrooms seem to be ok. My Sg is 1.025, ammonia 0ppm, nitrite 0ppm, nitrate 0ppm and pH is 8. I would like my pH to be a little higher but I don't think that would cause all this closing up. I do have some diatoms growing in the tank but it is slowly going away. I know all I tested for is the main stuff, is there anything else I should test for that may cause this? Oh and all my fish are perfectly happy and acting normal. let me know if there is something else I should test for and I'll go pick it up and test it right away. Thanks.

 

Check your zoas for nudis or bugs they will close cause of that.

 

There are no bugs in my tank and no parasites at all. My cleaner wrasse makes sure of that. I know my lighting isn't the problem because the corals were all in great shape since I got them and this morning. It was just this afternoon when they went downhill. Now all my zoas are all closed and even my mushrooms are shrivled looking.There was only one other time this had happened and it was when I did a water cvhange and I accidentally forgot to add water conditioner to the tap water. but I haven't done a water change in about a week, so I know that isn't the problem. What other parameter should i test for?