CO2 Scrubbing: An Unexpected Journey Chasing Numbers

[Ty Hamatake]

In

Of course it does, but my question was to those running an ATS, in particular, a waterfall design noticed a significant increase in their tanks PH level going up or otherwise. As we know algae take up CO2 but at what rate to make a significant effect on PH esp with an ATS ? Anybody with an Apex and the like (I haven't) able to report such readings?

Interesting... I hope someone has some info on this! Potentially an awesome 2-in-1 fix for high nutrients and low pH!

 

[atoll]

In

Interesting... I hope someone has some info on this! Potentially an awesome 2-in-1 fix for high nutrients and low pH!

Algae will also give off CO2 during the hours of darkness of course but with a waterfall ATS run 24/7 or near it the algae won't be given the chance to give off CO2 or if so only a limited amount of it and at a time when the DT lights are fully on for a period of the time the ATS is in darkness. I have a friend who was having an issue with low PH but after running his waterfall ATS for 2 weeks informs me his PH is steadily going up each day bit by bit.

 

[Ty Hamatake]

Algae will also give off CO2 during the hours of darkness of course but with a waterfall ATS run 24/7 or near it the algae won't be given the chance to give off CO2 or if so only a limited amount of it and at a time when the DT lights are fully on for a period of the time the ATS is in darkness. I have a friend who was having an issue with low PH but after running his waterfall ATS for 2 weeks informs me his PH is steadily going up each day bit by bit.

I take it he has no way to continually track it (pH monitor)? I'd definitely like to hear more detail!

 

[atoll]

I take it he has no way to continually track it (pH monitor)? I'd definitely like to hear more detail!

I am not sure but I think he has an apex I will ring him later to find out.

 

[Ty Hamatake]

I am not sure but I think he has an apex I will ring him later to find out.

Money.

 

[Randy Holmes-Farley]

Of course it does, but my question was to those running an ATS, in particular, a waterfall design noticed a significant increase in their tanks PH level going up or otherwise. As we know algae take up CO2 but at what rate to make a significant effect on PH esp with an ATS ? Anybody with an Apex and the like (I haven't) able to report such readings?

I've not seen data, but a waterfall ATS may be less efficient than other methods (e.g., growing macroalgae) since it is reaerated with high CO2 air.

 

[atoll]

I've not seen data, but a waterfall ATS may be less efficient than other methods (e.g., growing macroalgae) since it is reaerated with high CO2 air.

But then isn't that the same with a skimmer? If so a skimmer would reduce PH not increase it surly

 

[MockandRoll]

Great write up and I have been having very similar experiences. I have a 40 gallon tank with a CO2 scrubber and an Apex. I use the TLF 150 canister and find the lime is saturated around the 20-25 day mark. The problem that I am having is when the media is new or I leave for the weekend, I have to increase my 2 part dosing (due to increased pH) and then slowly decrease dosing amount as the soda lime becomes saturated. I am trying to figure out a way to program Apex Dos to slightly modify the dosing amounts based on the average daily pH reading. My plan was to change the dosing amount at midnight based on what the average pH was on the previous day. However, I was told this can not be done and I can only modify amount based on current pH reading. So I was thinking about basing dosing amount on peak pH reached. For instance if I want dosing amount to change from 35-40 ml, I could program something like this: "Set amount at 35 ml. If ph>8.15, set amount at 37 ml. If ph>8.2 set amount at 40 ml. Defer for 2 hours." I am sure there are many thinks wrong with this programming logic like the pH has to stay up for 2 hours before dosing is changed and once it drops again, dosing goes back to set rate. Does anyone have any other ideas on how to program this and on the possible downsides to doing this?

 

[Randy Holmes-Farley]

But then isn't that the same with a skimmer? If so a skimmer would reduce PH not increase it surly

Skimmers (without a CO2 scrubber) drive the pH toward equilibrium with the CO2 in the water and air. That can raise or lower the pH, depending on the circumstances. If the low pH is caused by high CO2 int eh home air (as it often is), then more aeration with that room air may lower pH, especially during the day when photosynthesizers are consuming CO2 in the water.

In my tank where I used limewater, the skimmer lowers the pH. When I turn it off, pH rises.

 

[Randy Holmes-Farley]

Great write up and I have been having very similar experiences. I have a 40 gallon tank with a CO2 scrubber and an Apex. I use the TLF 150 canister and find the lime is saturated around the 20-25 day mark. The problem that I am having is when the media is new or I leave for the weekend, I have to increase my 2 part dosing (due to increased pH) and then slowly decrease dosing amount as the soda lime becomes saturated. I am trying to figure out a way to program Apex Dos to slightly modify the dosing amounts based on the average daily pH reading. My plan was to change the dosing amount at midnight based on what the average pH was on the previous day. However, I was told this can not be done and I can only modify amount based on current pH reading. So I was thinking about basing dosing amount on peak pH reached. For instance if I want dosing amount to change from 35-40 ml, I could program something like this: "Set amount at 35 ml. If ph>8.15, set amount at 37 ml. If ph>8.2 set amount at 40 ml. Defer for 2 hours." I am sure there are many thinks wrong with this programming logic like the pH has to stay up for 2 hours before dosing is changed and once it drops again, dosing goes back to set rate. Does anyone have any other ideas on how to program this and on the possible downsides to doing this?

I think that might work. It is the elevated pH that is causing the demand increase, so using it to modify dosing may be reasonable. But make sure the effect is limited and couldn't cause a problem if the pH calibration drifted or something immediately messed with it (a power failure, a bubble, etc) and it got stuck in the low or high dosing scheme.

 

[Ty Hamatake]

In my tank where I used limewater, the skimmer lowers the pH. When I turn it off, pH rises.

This makes a lot of sense!

 

[Ty Hamatake]

Great write up and I have been having very similar experiences. I have a 40 gallon tank with a CO2 scrubber and an Apex. I use the TLF 150 canister and find the lime is saturated around the 20-25 day mark. The problem that I am having is when the media is new or I leave for the weekend, I have to increase my 2 part dosing (due to increased pH) and then slowly decrease dosing amount as the soda lime becomes saturated. I am trying to figure out a way to program Apex Dos to slightly modify the dosing amounts based on the average daily pH reading. My plan was to change the dosing amount at midnight based on what the average pH was on the previous day. However, I was told this can not be done and I can only modify amount based on current pH reading. So I was thinking about basing dosing amount on peak pH reached. For instance if I want dosing amount to change from 35-40 ml, I could program something like this: "Set amount at 35 ml. If ph>8.15, set amount at 37 ml. If ph>8.2 set amount at 40 ml. Defer for 2 hours." I am sure there are many thinks wrong with this programming logic like the pH has to stay up for 2 hours before dosing is changed and once it drops again, dosing goes back to set rate. Does anyone have any other ideas on how to program this and on the possible downsides to doing this?

Im glad Randy answered this. Im still a baby when it comes to programming!

 

[atoll]

If the low pH is caused by high CO2 int eh home air (as it often is), then more aeration with that room air may lower pH, especially during the day when photosynthesizers are consuming CO2 in the water.
.

Which as I understand it the PH will rise not fall due to photosynthesizers consuming the CO2 not lowering it or am I missing something here?

 

[Ty Hamatake]

Which as I understand it the PH will rise not fall due to photosynthesizers consuming the CO2 not lowering it or am I missing something here?

+1 slightly confused. I'm sure we know what he means and there is just a misunderstanding of how he wrote it and how we are interpreting it.

 

[atoll]

+1 slightly confused. I'm sure we know what he means and there is just a misunderstanding of how he wrote it and how we are interpreting it.

Thanks, well I am sure he will explain before we jump to the wrong conclusions hence my question.

 

[lariat8099]

Do you know if adding this CO2 scrubber would help lower my ORP? Currently my pH is right at 7.98 ORP is spiking to 460 to 465. Do you think this will help solve my issue? Thank you

 

[Ty Hamatake]

Do you know if adding this CO2 scrubber would help lower my ORP? Currently my pH is right at 7.98 ORP is spiking to 460 to 465. Do you think this will help solve my issue? Thank you

I don't know the first thing about ORP or how it works lol. Maybe Randy will come back with something more helpful.

 

[jason2459]

FWIW....

First great thread and a CO2 scrubber is a great option for many people that have low pH and can't drill a hole to the outside to draw in fresh air (or their fresh air isn't much better...).

I also run a CO2 scrubber and an ATS and limewater all working together to help my pH. The ATS helps the least amount of less then a pH of .1 but can be seen when it's taken offline. I used to run it 12 hours, 16 hours, and 18 hours mainly over the night hours but have gone full 24/7 with all the same impact on pH.

With out any intervention my pH is easily 7.8's and dipping to the 7.7's and much more so in the winters with the furnace and fireplace going and if more people are over breathing. I have a CO2 monitor and it's commonly well over 800 and into the 1000's

My primary means of increasing pH is my limewater dosing. I used to use limewater with my ATO but I found separating my ATO and limewater to help even more. The limewater dosing by itself is less then the evaporation rate but is consistently dosed. I have it dosing for 1 second every minute 24/7.

My next method of helping pH is my CO2 scrubber. I live in an area where I have no idea when pesticides or other chemicals are being sprayed around. I'm not going to pull in that air or rely on carbon. The CO2 scrubber has become almost just a necessity now for the Winters since splitting out my limewater dosing from the ATO making it more efficient.

No Intervention:
pH swings 7.7's to 7.9's

Limewater ATO by itself:
Sub 7.8 to ~8.0 swings daily with periodic spikes due to higher evap rates

Lime water ATO plus CO2 scrubber:
~8.0 to 8.3 swings daily with periodic spikes due to higher evap rates.

Lime water dosed separately under evaporation rate and NO CO2 scrubber:
~8.1-8.2 swings daily with no spikes due to increased evap rates.

Those were readings last fall. Since going through the Winter months
Lime water dosed separately under evaporation rate and NO CO2 scrubber:
~7.9-8.1 swings daily with no spikes due to increased evap rates

Limewater dosed separately under evap rate + CO2 scrubber
~8.0-8.2


If my pH was swinging a lot more then I'd look at boron additions but the swings seem fine to me.


As for the CO2 scrubber to make it more efficient I restrict the amount of air going through it. Also my new skimmer seems to be a lot more efficient at aeration then all my previous skimmers. Which I personally believe can be attributed to the injection method and the height of the skimmer.

For restricting I found full air draw from the skimmer just wastes the Sodalime with diminishing returns. So, I T off the skimmer's air line and put a valve on the air drawn from the CO2 scrubber. The other line off the T is not restricted at all so the skimmer is still getting it's full air draw.

Here's my setup with a CO2 scrubber and ozone (ozone isn't part of this and I have never seen any impact on pH with it.)
https://www.reef2reef.com/threads/mtc-mvx-skimmer-review.252436/page-4#post-3101922


And a follow up post on my belief in the injection and dwell time working together to make the most of the CO2 scrubber (which I could be entirely wrong about the injector thing but my results are positive.)
https://www.reef2reef.com/threads/mtc-mvx-skimmer-review.252436/page-9#post-3671848

 

[jason2459]

Do you know if adding this CO2 scrubber would help lower my ORP? Currently my pH is right at 7.98 ORP is spiking to 460 to 465. Do you think this will help solve my issue? Thank you

I have found no impact directly related to ORP and the CO2 scrubber.

If you are not dosing anything oxidizing like Ozone/UV/H2O2/etc increasing ORP I would not worry about the ORP.

 

[MockandRoll]

I think that might work. It is the elevated pH that is causing the demand increase, so using it to modify dosing may be reasonable. But make sure the effect is limited and couldn't cause a problem if the pH calibration drifted or something immediately messed with it (a power failure, a bubble, etc) and it got stuck in the low or high dosing scheme.

I am thinking to program so the pH reading can only slightly vary the dosing amount (~3-5 ml daily) so hopefully it can't cause large problems. I asked for programming help in neptune's forum so we'll see if someone can help me with the programming.