Algae Scrubber and Alkalinity

[Picano]

I run an algae scrubber on a 110g tank as the sole filtration system. I've come into a problem...

Here's my system parameters with Salifert test kits:

Nitrate: 0ppm
Phosphate: 0.025 or less
pH: 8.2 constant
Magnesium: 1400ppm
Calcium: 400ppm
Alkalinity: 7dKh

I have never dosed this tank with a calcium and alkalinity product like B-Ionic or a Kalkwasser drip. I pretty much rely on water changes.

This is the only parameter that I can't get to stay up. Do ya'll think it's worth taking the time to put the tank on a kalkwasser drip or would a two part solution be the best to use once a week? I need some ideas.

 

[Picano]

I'm getting mixed ideas here. Some people say it does use alkalinity, others say it has nothing to do with it. Who do I believe? In any case, if my calcium and alkalinity is that low, I probably need to balance it and increase it, neh?

 

[spamreefnew]

its not that low. nsw is 400 & 8 ish.

my scrubber has not changed my ca&alk

maybe because things like coraline and corals are growing they are using more?

maybe the salt mix has a little less this time around