How can I keep my ph up?

[reefy]

I cant keep my ph high, 7.95=light on 7.80=light off(refugium light on) I do add ph buffer often. I am currently dripping Kalkwasser 1 drop per second. here is my current water parameter:
nitrate=0
phosphate=0
temp=76.2
Ph=7.80 (light off)
calc=460-470
mag=1500
dkh=5.5 low will add buffer right now

now my question is can I drip ph buffer? I think its a risky move isnt it? what do you guys do to keep your ph to 8.1-8.3? it seems imposible to me.