CO2 Scrubber --> increase ph --> faster alk depletion?

[Gabbone]

Hi guys,

I have a question for the experts!

I have a 30g 4 month tank packed with LPS and some softies. Everything is thriving and growing so far.

I wanted to experiment and I was thinking to increase my PH; I bought a CO2 scrubber (the one you attach to the skimmer air intake). Ph increased from 8.0/8.1 to 8.4/8.5 but then my ALK daily consumption dramatically increase to 0.5dkh a day. Is that normal?

I measured my Dkh yesterday morning and was 8.5. I dosed 5ml of RedSea Alk B and Alk back up to 9.0.
This morning, again, at 8.5. and so on. I don't have SPS.

Is this faster Dkh depletion is due to higher PH or it will happens as the tank mature? Everything happened in a matters of since since couple of weeks ago my Dkh was around 10.5. Should I remove the co2 scrubber?

Another weird thing is that I use Red Sea Coral Pro Salt which should have a Dkh of 11.5. For the first 3 months Alk was always at 11.0 but now it stays around 8-9dkh despite the use of Coral Pro Salt.

Any thoughts?

Thank you so much in advance!

Ciao!

 

[Gabbone]

Little correction;

*Ph increased from 8.0/8.1 to 8.2/8.3*.

I've been testing the ph on the 27-04, 06-05 and 11-05 and ph was always stable at 8.3

 

[dangles]

I’m new too but just relaying what I’ve read about, so don’t take this as gospel

Increasing pH can increase growth rate, which in turn would increase alk consumption. Same with Ca/Mg and other minor/traces.

 

[Gabbone]

Thanks for the comment. I've also read that but we are talking about 0.5dkh depletion per day which I believe is abnormal for a young LPS/Softies tank.

 

[Randy Holmes-Farley]

Increased pH increases both biological calcification and abiotic precipitation of calcium carbonate.

 

[Gabbone]

Thanks Randy! So is this normal?
Could you maybe explain me what is an “abiotic precipitation of cc”?

Kind regards

 

[Randy Holmes-Farley]

Thanks Randy! So is this normal?
Could you maybe explain me what is an “abiotic precipitation of cc”?

Kind regards

Yes, it is normal.

Abiotic (nonbiological) precipitation is calcium and carbonate binding onto and growing a crust on existing calcium carbonate surfaces or warm objects like heaters or pumps. In a bad precipitation event it happens in the bulk water too, turning it milky white.

High alk, pH, and to a small extent calcium promote it, while high phosphate, magnesium, organics and bacteria all deter it.

 

[Gabbone]

All clear. Thank you a lot for the explanation. Then it’s time to serious start daily dosing Alk.

One more thing, in which cases I should be worried?

 

[Randy Holmes-Farley]

All clear. Thank you a lot for the explanation. Then it’s time to serious start daily dosing Alk.

One more thing, in which cases I should be worried?

Hardening sand or inability to maintain alk with reasonable alk doses.

 

[PeterC99]

All clear. Thank you a lot for the explanation. Then it’s time to serious start daily dosing Alk.

One more thing, in which cases I should be worried?

I think you will find the CO2 scrubber the right path to go. Higher pH and Alk consumption will significantly increase growth.

Many people use Kalk for this purpose but I found Kalk very difficult to keep consistent.

The kind of CO2 scrubber you bought is a recirculating scrubber. This will significantly reduce the need to change out the media frequently. Keep an eye on the Calc & Alk. As the growth increases so will the Calc & Alk consumption.