Ph, kh issues

[mainereefer]

I started testing because I have corals bleaching looks like I'm having I'm having issues with kh and ph....
No matter what I do I cant get ph above 7.8 and kh wont go above 7

I'm dosing kh twice a day it should bring it up by about .5-1 each time but I'm testing when lights are off out and with lights on and not much change... it's been 4 days with no change

Mixed reef lps, zoa, shrooms....

 

[blaxsun]

What kind of test kits are you using?

 

[mainereefer]

Junk api.... but red sea at lfs is saying the same

 

[HuduVudu]

What are you dosing?
What is your household CO2?

 

[Pistondog]

Do you have a skimmer? If not try an airstone to help gas exchange.
I'm guessing windows are open, so not an ambient co2 problem

 

[mainereefer]

Windows are open 24/7 this time of year.
No sump or skimmer, fluval 304 with scwd return and a wavemaker
Plenty of water surface movement...
Nitrate about 10
Po4 just showing on test so less than .25
Calcium is about 440

I'm at a loss... thinking about doing a few big waterchange's this week