As a few others have stated your tank is new. I know and see you have other things in the tank.
The issue is there is not a protective layer on the rock and the rock can be leaching off items that we can not measure for, as we measure the water at the top of the tank, compared to right on/off the rock.
Once it colors up, non-white, then it is showing a protective/productive layer. This layer actually works as the biological filter. Not only working on what is in the tank, but what is coming off the rock.
Most people say at least 6 months., This gives it time for the rock to season and beneficial bacteria able to handle almost anything to be built up.
Sorry about the anemone.
Please feel free to post away and ask questions. There have been many here that have been in your shoes before.
Be leary of impulse buying. Also QT anything and everything that you put in your tank. A bad item can wreck havoc on an entire tank.
Good luck!
So tell us about the tank.