Ricordea Florida not opening

[CThomas1026]

I added a Koralia Nano (240gph) to my 14 biocube 3 days ago. Since then, my ricordea hasn't opened fully. I suspected it wasn't enjoying all the flow, so I moved it to a calmer section but it has been 2 days and still looks the same. Also, today, it appeared a bit darker than usual. Any ideas?

 

[Alysiak00]

"ruh roh!" sounds like decay to me

 

[CThomas1026]

So what action should I take? I did a water change last week (when I put in the koralia), but should I do another?

Parameters for the tank are fine, except the pH dropped to 7.8 for some reason. Could this be the cause? All the other corals (other mushrooms, zoos, and a bubble) are doing fine.