Calcium won’t rise

[ReefingDaily]

Hey everyone,

After searching various forms I haven’t been able to find an answer to my current issue. I have a 29g Biocube that is mainly softies and few smaller lps frags that aren’t very large yet, but are clearly growing. I also have a few small digitata frags.

This issue is that water change after water change I can’t seem to get my calcium past 400ppm. I’ve been doing bi-weekly water changes for over a month and still calcium won’t seem to budge when testing 24hrs after. Even after doing a 35% water change there wasn’t any increase in Ca. I’ve tested the saltwater going in and Ca reads ~460 ppm. Not sure if anything is precipitating out because there’s no way my corals are consuming that much that quickly.

Ca:360-380 ppm
kH: 8 (Increased from 7 to 8 dKH after 35% wc)
Nitrate: 5ppm
PO4: <0.25 (no Hanna checker)
Salinity: 35 ppt
Mg: 1400
Temp: 77.6 f
Salt: Reef Crystals

Could really use some input!

 

[Little_Red_Ryan_Hood]

Are you dosing some form of Cal and Alk in between water changes?

 

[spidercrab]

Dose it and it will go up quickly.

 

[Topekoms]

Water changes are not adequate for raising levels for example if you do a 35% water change you are only adding a small portion of CAL back to the tank. You will need to start dosing Alk, Cal independently from water changes to raise it. I use BRS 2 part myself

 

[ReefingDaily]

Not currently dosing anything. Will I have to continuously dose? Or just temporarily?

 

[Little_Red_Ryan_Hood]

If you raise your dkh 1 full point during a water change, then calcium would only raises about 7 ppm.

 

[Little_Red_Ryan_Hood]

Continuous

 

[Little_Red_Ryan_Hood]

This should help

 

[ReefingDaily]

Interesting! I really didn’t think I would have to dose. Would a 75% water change help get the levels up? And then use Kalkwasser to maintain?

 

[Little_Red_Ryan_Hood]

If that is the way you want to go about it. I would not do 75 percent all at once though. Break it up into smaller changes every other day. You don't want to create other issues by doing that large of a water change.
This will not be the last time you have to adjust your levels. Picking up some 2 part will be cheaper in the long run and it would follow the advice a few experienced reefers have given you.
Even if you use kalk to maintain your levels, they will get out of balance again.

 

[Randy Holmes-Farley Verified Community Expert]

Interesting! I really didn’t think I would have to dose. Would a 75% water change help get the levels up? And then use Kalkwasser to maintain?

water changes with a mix that matches your goal can never solve the problem. It will fall farther and farther behind. Dosing is easy. Everyone does it. Alkalinity dosing is even more important.

kalkwasser dosing works fine, but isn’t necessarily easier.

 

[ReefingDaily]

Thanks for the advice everyone. Planning on making some two part following Randy's instructions. I guess my consumption rate is much larger than I realized. I can only imagine what it will be like once those frags turn to colonies.