Anemone shrinks

[Bling4Drift]

Hello. Thats normal that my anemone at the day feels very good, but at night shrinks a lot.
200l tank with sump.
5 nitrate
0.03 phosphate
1.024 salinity
Ph 8.24
Temp 0.24C

 

[Quietman]

My BTAs are open during day and will close at night or sometimes after feeding or sometimes when bothered by fish. Pretty normal. If they don't like where they, they'll move and let you know by constant movement that you need to provide more/less light or more/less flow.