Help me understand alk/calcium consumption and dosing

[The_Skrimp]

Hi folks.
So my tank is currently:
50gal mixed reef
Calcium 480
Alk 8.5
Mag 1450
Nitrates 0.5
Phosphates 0.3
Ph 8.15
Sal 1.026
Temp 78.5

the calcium is high because I use reef crystals which has high calcium to start with but since things seem to be going fine in my tank, I’ve just been trying to maintaining at those numbers.

I started out using only kalk to maintain them but…
Here’s the problem:

If I dose enough kalk to maintain alk at 8.5 my calcium starts to shoot upward. If I lower my dosage to maintain calcium at 480, my alkalinity starts dropping by about .5dkh per day.

The consumption just doesn’t seem to be in balance however I didn’t think it should be possible for them to be that far off.

the only way I’ve been able to fix this is to dose both kalk and about 7mls extra of soda ash every day.

I’m mostly hoping someone can double check what I’m doing and let me know if I’m going about this the wrong way.

I have considered switching to All For Reef because I’ve read on a Reddit forum that it helps to balance things out once your tank hits whatever numbers are stable for it.

Can folks help me understand this?
Is it my acros growing that are consuming extra alk?

thanks so much!

 

[arking_mark]

Hi folks.
So my tank is currently:
50gal mixed reef
Calcium 480
Alk 8.5
Mag 1450
Nitrates 0.5
Phosphates 0.3
Ph 8.15
Sal 1.026
Temp 78.5

the calcium is high because I use reef crystals which has high calcium to start with but since things seem to be going fine in my tank, I’ve just been trying to maintaining at those numbers.

I started out using only kalk to maintain them but…
Here’s the problem:

If I dose enough kalk to maintain alk at 8.5 my calcium starts to shoot upward. If I lower my dosage to maintain calcium at 480, my alkalinity starts dropping by about .5dkh per day.

The consumption just doesn’t seem to be in balance however I didn’t think it should be possible for them to be that far off.

the only way I’ve been able to fix this is to dose both kalk and about 7mls extra of soda ash every day.

I’m mostly hoping someone can double check what I’m doing and let me know if I’m going about this the wrong way.

I have considered switching to All For Reef because I’ve read on a Reddit forum that it helps to balance things out once your tank hits whatever numbers are stable for it.

Can folks help me understand this?
Is it my acros growing that are consuming extra alk?

thanks so much!

How to balance Ca/Alk in the reef aquarium?

After reading: http://www.reefkeeping.com/issues/2004-12/rhf/ Here are my takeaways: For most practical purposes, Ca and Alk are consumed equally. However, "...the demand for calcium and alkalinity may not be precisely balanced at 20 ppm calcium per 1 meq/l of alkalinity..." The biggest...

www.reef2reef.com

 

[The_Skrimp]

That’s perfect! Thank you for the link.

 

[arking_mark]

That’s perfect! Thank you for the link.

This is how I ended up rebalancing...

How to balance Ca/Alk in the reef aquarium?

FWIW, the slow calcium rise is expected with limewater (kalkwasser). I used a low calcium mix (normal IO) for that reason. If you want the same pH effect as the kalkwasser, you'll need to use sodium hydroxide. If you just want the same alk effect, then you can use bicarbonate, carbonate, or...

www.reef2reef.com