Thoughts on pH and CO2 scrubber

Cthulukelele · Jun 20, 2019

So I have been considering setting up a CO2 scrubber after reading a bit about the chemical relationship between pH and calcium deposition.

I run a pH somewhere between 7.85 and 8.05 depending on the time of day, and I was wondering what experiences people have had with the effectiveness of CO2 scrubber in raising pH.

I was also thinking about gluing a 3/8" valve over one or the overflows on my skimmer lid to recycle air and save on co2 media cost. Is this a bad idea? I'd keep the scrubber elevated as to avoid sucking in skimmer overflow.

120reefkeeper · Jun 20, 2019

It works for sure. Please check out my article.

https://www.reef2reef.com/ams/low-ph-issues-make-your-own-co2-scrubber.92/

kirbuno · Jun 20, 2019

120reefkeeper said:
It works for sure. Please check out my article.

https://www.reef2reef.com/ams/low-ph-issues-make-your-own-co2-scrubber.92/

Not following the concept discussed, and I don't seem to have permission to the follow the link for the discussion article. Can you elaborate?

saltyhog · Jun 20, 2019

Unless you have a very "tight" house I don't see the need. Run a skimmer, point power heads or return lines so they ripple the surface, etc. There is nothing wrong with where your pH is now. Chasing a pH number is not helpful IMO and can hurt (buffers).

Cthulukelele · Jun 20, 2019

saltyhog said:
Unless you have a very "tight" house I don't see the need. Run a skimmer, point power heads or return lines so they ripple the surface, etc. There is nothing wrong with where your pH is now. Chasing a pH number is not helpful IMO and can hurt (buffers).

I agree that doing any sort of chemical buffering is almost strictly detrimental, but am I misunderstanding calcium deposition? My understanding is that increased pH pushes calcium carbonate deposition which would theoretically increase coral growth.

I was also under the impression that the vast majority of low pH problems for reef tanks had to do with ambient CO2 levels in the home being well above what is found outside. My tank is quite high flow, and water agitation isn't an issue.

I guess I'm more curious if anyone sees the THEORETICAL benefits of CO2 scrubbing occurring IN PRACTICE with a higher and more stable pH.

Cthulukelele · Jun 20, 2019

And to be clear, I expect it to increase my pH by .2 or so, but I'm curious if people see the increase in calcium usage and coral growth that would theoretically accompany that pH and stability increase.

120reefkeeper · Jun 20, 2019

kirbuno said:
Not following the concept discussed, and I don't seem to have permission to the follow the link for the discussion article. Can you elaborate?

The concept discussed is how to remove carbon dioxide from a reef tank using either a fresh air source or C02 scrubbing media. If you live in a tight home or you cant always open windows , then a Co2 scrubber can help. Also noted in my results were increased growth of coral due to the ability of better alkalinity and calcium uptake. Excess Co2 makes it more difficult for our corals to calcify . Increasing Ph makes it easier for them to do just that.

lets try this link again.

https://www.reef2reef.com/ams/low-ph-issues-make-your-own-co2-scrubber.92/

ca1ore · Jun 20, 2019

Just be prepared for it to make no difference. Hopefully in your case it will, but depending on tank desigh and location, it may not. Doesn’t for me.

120reefkeeper · Jun 20, 2019

Cthulukelele said:
And to be clear, I expect it to increase my pH by .2 or so, but I'm curious if people see the increase in calcium usage and coral growth that would theoretically accompany that pH and stability increase.

this is exactly what ive seen. Increased growth and better stability. This is not a new concept . Folks like Anthony Calfo and several others have written about it over the years, whats new is we understand it better and have found some useful tools to help us deal with excess C02.

120reefkeeper · Jun 20, 2019

saltyhog · Jun 20, 2019

Cthulukelele said:
And to be clear, I expect it to increase my pH by .2 or so, but I'm curious if people see the increase in calcium usage and coral growth that would theoretically accompany that pH and stability increase.

I really can't say for my tank as my pH has always been between 8.1 and 8.4(with the nadir being early in the morning before lights are on). That's considerably higher than the oceans the corals come from....at least surface pH. I do notice that if we have a large gathering of 20-25 people in the house my graph will go down about 0.1. Those darn CO2 expelling humans!

120reefkeeper · Jun 20, 2019

kirbuno · Jun 20, 2019

I guess I understand the concept of co2 removal. I've tried using a co2 scrubber, but the media only lasts a few days. So to me with me time constraints it is not feasible.

What I wasn't following was the comment:

"I was also thinking about gluing a 3/8" valve over one or the overflows on my skimmer lid to recycle air and save on co2 media cost."

Which sounds good. Tried your link again, still gives me:

"You don't have enough permission to access this feature"

Maybe it's a forum I'm not a member of.

120reefkeeper · Jun 20, 2019

kirbuno said:
I guess I understand the concept of co2 removal. I've tried using a co2 scrubber, but the media only lasts a few days. So to me with me time constraints it is not feasible.

What I wasn't following was the comment:

"I was also thinking about gluing a 3/8" valve over one or the overflows on my skimmer lid to recycle air and save on co2 media cost."

Which sounds good. Tried your link again, still gives me:

"You don't have enough permission to access this feature"

Maybe it's a forum I'm not a member of.

Maybe your trying to access the link via a phone??

kirbuno · Jun 20, 2019

Yes. Didn't know that was a problem. Haven't had issues before. I'll try later via a computer.

vic5hands · Jun 20, 2019

plea

120reefkeeper said:
It works for sure. Please check out my article.

https://www.reef2reef.com/ams/low-ph-issues-make-your-own-co2-scrubber.92/[/QUOTE
please post pictures Thank you

Cthulukelele · Jun 20, 2019

kirbuno said:
I guess I understand the concept of co2 removal. I've tried using a co2 scrubber, but the media only lasts a few days. So to me with me time constraints it is not feasible.

What I wasn't following was the comment:

"I was also thinking about gluing a 3/8" valve over one or the overflows on my skimmer lid to recycle air and save on co2 media cost."

Which sounds good. Tried your link again, still gives me:

"You don't have enough permission to access this feature"

Maybe it's a forum I'm not a member of.

I have heard reusing the air coming through your skimmer greatly increases the longevity of the scrubbing media. The idea is that if you lower co2 in the water, the air exchanged with the water flowing through your skimmer should come out with lower co2 than the general air in the room, so if you can "recycle" that air in a closed system, the media will last longer.

You know the overflow holes on top of a skimmer lid? I was thinking I could attacy 3/8" tubing over one and use that to create a closed humid loop and conserve co2 absorbing media. Obviously you have to be smart about it because if the co2 scrubber was below your skimmer and it overflowed, you'd create a siphon pulling water through that soda lime and back into your tank which would likely skyrocket your pH.

Does that make sense? I'm not the best explainer.

ca1ore · Jun 21, 2019

I do not know whether recycling the air through your skimmer will make CO2 scrubbing media last longer, but it certainly helps to prevent clogging of the venturi. Lifereef has been doing this on their skimmers for years.

DangerDave · Jun 21, 2019

Using the air from your skimmer keeps moist air flowing through the C02 reactor extending the life of the media. I currently run the air through a reactor filled with water for the same effect.

JDowns · Jun 21, 2019

ca1ore said:
I do not know whether recycling the air through your skimmer will make CO2 scrubbing media last longer, but it certainly helps to prevent clogging of the venturi. Lifereef has been doing this on their skimmers for years.

I saw a doubling of the media life in testing when recirculating through the skimmer. The result is a lower CO2 concentration entering the media chamber and the added humidity improves the media efficiency.

Mileage on Ph improvements will vary depending on skimmer size and setup. A larger skimmer in the same setup will result in a lower Ph result, simply due to the fact that more air is drawn faster through the media reducing contact time. When I wet skim to counter act salinity increases due to 2 Part dosing and Kalk dosing, Ph will drop. This is because I increase the motor speed since it is a DC pump.