Co2 Scrubber

[USMA36]

How long should it take before I notice a raise in my Ph? I have had the Co2 scrubber hooked up to my skimmer about 4 hours and I haven't noticed any difference in my pH. I didn't think it would be instant, but I was expecting a slight rise by now.

 

[Paullawr]

Hi,

Don't expect a massive change in pH. The AVG should go up providing co2 is the source of the low ph to begin with.

Have you tried opening Windows, increased surface agitation, air stone running air line outside first. (Usual tricks to determine it is co2).

How are you taking your readings, probe manually or say apex. The latter would be easier to chart peaks.

Lastly you should notice an improvement on recordings over a 24 hour day.

 

[nervousmonkey]

How long should it take before I notice a raise in my Ph? I have had the Co2 scrubber hooked up to my skimmer about 4 hours and I haven't noticed any difference in my pH. I didn't think it would be instant, but I was expecting a slight rise by now.

Wait a few more hours; you will really see a change by overnight and tomorrow morning. Remember your tank has a lot of residual CO2 in it. The CO2 scrubber doesn't scrub the tank water (which is an obvious statement), so you have to wait until your tank has had the opportunity to blow off the remaining CO2. Giving it time overnight is usually the best way to see a change. And like Paul said, how are you measuring it? If by apex it'll be easier to see changes, esp. overnight with the normal valleys you would get starting to flatten out some, not all the way, but less height to the change in pH.

 

[Gator1970]

Please let us know if it makes a difference overnight - I am considering using a scrubber at night to help minimize ph swings.

 

[SuperDragon]

You should give your tank up to 24 hours to see a change. Others may see it quicker.
My thread below has most of your answers.
https://www.reef2reef.com/threads/co2-scrubber-review.296392/page-5#post-3670690

 

[nervousmonkey]

Please let us know if it makes a difference overnight - I am considering using a scrubber at night to help minimize ph swings.

I did not mean to imply that CO2 scrubbing happens at night, what I meant was wait until the morning before looking for pH changes. You are thinking about CO2 scrubbing the wrong way; it does not scrub the water, just the air going into the water, so there is a delay between when you see the shift in pH and when the CO2 scrubber is initially started. The CO2 has to get out of the water. If you scrubbed only at night, you would see an even worse pH swing because by the time morning came, you would have given enough time to get enough of the CO2 out of the water to effect a pH change upwards, so you'd have great daytime pH highs, and while it was not scrubbing during the day, you would slowly allow CO2 to build back up in your tank, causing a drop at night again. You need to run the CO2 scrubber all the time to see any changes, and even then, you will see a pH swing, but who cares? The ocean has pH swings. You want to keep CO2 out of your tank period; the acidity of dissolved CO2 into carbonic acid wreaks havoc on calcium carbonate.
Listen to @SuperDragon and please read his thread, it's really good information, and should some of you be worried about too high a pH level, he has a solution.

 

[Gator1970]

I did not mean to imply that CO2 scrubbing happens at night, what I meant was wait until the morning before looking for pH changes. You are thinking about CO2 scrubbing the wrong way; it does not scrub the water, just the air going into the water, so there is a delay between when you see the shift in pH and when the CO2 scrubber is initially started. The CO2 has to get out of the water. If you scrubbed only at night, you would see an even worse pH swing because by the time morning came, you would have given enough time to get enough of the CO2 out of the water to effect a pH change upwards, so you'd have great daytime pH highs, and while it was not scrubbing during the day, you would slowly allow CO2 to build back up in your tank, causing a drop at night again. You need to run the CO2 scrubber all the time to see any changes, and even then, you will see a pH swing, but who cares? The ocean has pH swings. You want to keep CO2 out of your tank period; the acidity of dissolved CO2 into carbonic acid wreaks havoc on calcium carbonate.
Listen to @SuperDragon and please read his thread, it's really good information, and should some of you be worried about too high a pH level, he has a solution.

Oh, I understand how co2 scrubbing happens. I am looking at ways of stabilizing my ph swing at night due to photosynthesis ceasing. I am going to add a refugium as well, and operate opposite to display lighting. I am not looking to eliminate the swing entirely - I want to moderate it. Right now I am getting quite a swing - up to 0.3 - I consider that excessive.

 

[nervousmonkey]

Ok good. A refugium on opposite lighting will help more than anything. It won't help to turn on the scrubber at night; it would be more effective to run it during the day only so when evening/night comes around, your tank is free of CO2 and subsequent pH level higher, then during the day by the time CO2 has built back up, photosynthesis takes over and starts raising your pH again. My only point is that takes time to reduce the CO2 in ones tank enough that pH can reflect the level of CO2. This is due to the non-linear, logarithmic nature of calculating pH. CO2 has to decrease by 10 times to inrease pH by one point. Anyway, it would be healthier for your tank to run a CO2 scrubber 24/7 and run a reverse light schedule refugium if you want to minimize pH swings.

 

[Gator1970]

Ok good. A refugium on opposite lighting will help more than anything. It won't help to turn on the scrubber at night; it would be more effective to run it during the day only so when evening/night comes around, your tank is free of CO2 and subsequent pH level higher, then during the day by the time CO2 has built back up, photosynthesis takes over and starts raising your pH again. My only point is that takes time to reduce the CO2 in ones tank enough that pH can reflect the level of CO2. This is due to the non-linear, logarithmic nature of calculating pH. CO2 has to decrease by 10 times to inrease pH by one point. Anyway, it would be healthier for your tank to run a CO2 scrubber 24/7 and run a reverse light schedule refugium if you want to minimize pH swings.

Thanks - that's very helpful!

 

[USMA36]

The scrubber has been up and running 24 hours with no difference to the pH. Any ideas?

 

[nervousmonkey]

How do you have it connected? First just making sure it's pulling in air through the scrubber properly. I have rarely seen a CO2 scrubber make no difference at all, meaning that you have no CO2 to scrub out of the ambient air around the tank. Actually I have never seen it happen. I'm not doubting you, but would you mind taking a picture of how you have it connected to your skimmer?

 

[SuperDragon]

The scrubber has been up and running 24 hours with no difference to the pH. Any ideas?

Did you add the required 1tbsp of RODI water to the chamber of the filter? http://www.bulkreefsupply.com/brs-universal-co2-scrubber.html
Sorbs need moisture in the air to work. There is a better way to add moist air though, but more involved.

 

[USMA36]

I have the air line from the skimmer connected to the left side of the brs scrubber. I added 1 tbsp of water to the bottom of the outer canister as brs recommends.

 

[Gablami]

I would also add that if your skimmer is undersized for your tank, or not running at full strength (for DC pumps) that can affect the effectiveness of CO2 scrubber. I upgraded my skimmer and noticed a big jump in the pH and also went through my media much faster.

 

[Gablami]

I have the air line from the skimmer connected to the left side of the brs scrubber. I added 1 tbsp of water to the bottom of the outer canister as brs recommends.

This might seem silly, but your canister is inserted in the correct orientation right? Lastly, do you see any color change at the bottom? If there is no color change over time (if you're using media that turns purple) it is not extracting CO2.

 

[USMA36]

I just took it apart to make sure. Cap is on the bottom. Brs directions said one teaspoon of water in the outer container. Others said add between 1 and 2 as long as media stays dry. I added 2. I also ran hose outside of sump so the intake would get more airflow.

 

[jsker]

I am calling in someone I trust on this @120reefkeeper here is his article about Co2 scrubbers link

 

[Gablami]

I just took it apart to make sure. Cap is on the bottom. Brs directions said one teaspoon of water in the outer container. Others said add between 1 and 2 as long as media stays dry. I added 2. I also ran hose outside of sump so the intake would get more airflow.

Any color change? Also I can usually feel/head the air flow running through the scrubber if you place your finger at the intake kynar barb. If there is airflow through the system and not a large leak along the path into your skimmer, it should be scrubbing the CO2, unless you live in an oxygen canister.

So then it's just a matter of whether the skimmer pump is powerful enough relative to the size of your tank to show a difference. What numbers are we talking about? Perhaps the pH is already on the higher side, and subsequent change will be more difficult to tell since pH is on a logarithmic scale. Also, maybe we should start exploring how you are testing for pH. Sorry if you mentioned some of this in earlier posts.

One additional thought is what diameter of tubing you're using. I use 1/2 inch. If it's narrow and long (because you mentioned extending it) it can reduce the efficiency of your skimmer.

 

[nervousmonkey]

Great point Gablami. USMA, when you plug the airline on your skimmer without the scrubber attached, what does it do? The water level should begin rising in the skimmer and you should hear some kind of noise, at least I do. Now plug the intake of the scrubber canister and see if the same thing happens. If it does, you have good airflow through your skimmer, if it doesn't, you don't. Your skimmer pump may not be powerful enough to pull the air through the skimmer; there are some skimmers that advertise not to extend the airline more than 6 feet from the pump as it will not work as effectively, and that *may* be the case, although I don't think so.
Another trick to try and get more airflow is to remove the barb fitting that screws into the intake part of the scrubber canister, so you have more airflow right at the beginning.

If all this fails, then there is something wrong with the equipment or set up. A CO2 scrubber will always show some kind of pH change, as even outside air has a high enough concentration of CO2 to drop the pH somewhat.
You could try running the line outside as well to see if that makes a difference. If it does, then your canister set up is not correct, or is not working well.
One more thing, on those BRS canisters, there are typically two sponges. Remove both of the big sponges, check to see if there is debris or if they are wet and not allowing airflow through them.
Last, can you post pictures of your canister set up?
Last last, how big is your tank and what skimmer are you using with what pump? That may help answer some questions.

 

[120reefkeeper]

Great point Gablami. USMA, when you plug the airline on your skimmer without the scrubber attached, what does it do? The water level should begin rising in the skimmer and you should hear some kind of noise, at least I do. Now plug the intake of the scrubber canister and see if the same thing happens. If it does, you have good airflow through your skimmer, if it doesn't, you don't. Your skimmer pump may not be powerful enough to pull the air through the skimmer; there are some skimmers that advertise not to extend the airline more than 6 feet from the pump as it will not work as effectively, and that *may* be the case, although I don't think so.
Another trick to try and get more airflow is to remove the barb fitting that screws into the intake part of the scrubber canister, so you have more airflow right at the beginning.

If all this fails, then there is something wrong with the equipment or set up. A CO2 scrubber will always show some kind of pH change, as even outside air has a high enough concentration of CO2 to drop the pH somewhat.
You could try running the line outside as well to see if that makes a difference. If it does, then your canister set up is not correct, or is not working well.
One more thing, on those BRS canisters, there are typically two sponges. Remove both of the big sponges, check to see if there is debris or if they are wet and not allowing airflow through them.
Last, can you post pictures of your canister set up?
Last last, how big is your tank and what skimmer are you using with what pump? That may help answer some questions.

Lots of good questions here.


Let us know if your still having issues.