Baffled by calcium and alk consumption

[rhymechizel]

I started my first reef tank in about 2005 but took a long break when I went to school and I’m now just getting back into it. My tank has been running for about 7 months now. It’s 105g planet aquarium. I filled the tank with reef crystals salt and That’s the salt I’ve used until about two weeks ago. I didn’t check calcium or Alk for the first 4 months or so. I added a lot of frags of a variety of coral including zoas, palys, SPS chalices and other LPS at about the 3 month mark and have continued to add coral since then. My tank is actually doing really well and frags that I got that were once brown are now colored up and things are growing. I’m baffled though that I’ve only dosed calcium a handful of times during the last three months and alk doesn’t budge from 9. I switched to Red Sea (non-coral pro) because about two weeks ago I did a water change and my calcium went from 480 to 520 and now it’s just sitting at 520. During that water change my alk went to 11 but then settled back to 9 after a couple days. I’m just baffled because I see coral growth and coralline algae is sprout all over

but my calcium and Alk are rock solid and I actually want to run them at a lower number but they just won’t drop.

Ca 520 Hanna
Alk 9 Hanna
Mg 1500 Red Sea
Phos .02-.06 Hanna
Nitrate 10 Red Sea
Salinity 35
Ph 7.9-8.1
Temp 78-80

 

[ndrwater]

Sounds pretty normal to me. Ikkw slts like RC & RS Pro mix quite a bit higher than things like regular IO, ut see to settle down after a couple of days. Part of the reason I use regular IO. It mixes and stays closer to where I keep my parameters

 

[rhymechizel]

Sounds pretty normal to me. Ikkw slts like RC & RS Pro mix quite a bit higher than things like regular IO, ut see to settle down after a couple of days. Part of the reason I use regular IO. It mixes and stays closer to where I keep my parameters

Thanks! That’s kinda what I was thinking but just hoping for validation