Issue keeping ph and calcium stable

[spencerfe2010]

Hey all I have a 240g 5 months old water parameters are all good. The only issue I am having is keeping my 8.0-8.4 ph, it usually drops daily to 7.89 and hovers there. I dose alk 4 times a day at 200ml total daily. I can’t keep it to stay at above an 8. Calcium I dose 75ml a day and it constantly goes from 550 to Calcium 350… it won’t stay above 350. I do 15-20% water changes every Sunday i have a auto top off that does 10gallons weekly….. . I have carbon media going daily, a uv filter with low flow, 2 filter sock, and my Red Sea 900 skimmer.
I honestly can’t figure it out. Just constantly drops every single day!

 

[MamaMolo]

What are you dosing? 2 Part? Do you dose nitrates? Have you tried running an airline outside through your skimmer?

 

[mdb_talon]

Sounds like you have some testing and/or precipitation issues. No reason calc would be dripping 550 to 350 a day. Are you dosing alk/calc at the same time? What product are you dosing 200ml and 75ml of?