CO2 scrubber disappointing results

[coastal_kid]

I set up a CO2 scrubber this week (see picture). It pull air from the skimmer cup and supplies the skimmer pump.
You can see from the bubbles in the skimmer that it is getting air.
There is condensation in the tubes so I know that it is kept moist.

Here is what it did for my PH:

I'm getting about a 0.1 bump in PH during the night.
I was hoping to get a get a much bigger bump.

I'm using Jorgensen soda lime.
Display tank is 180g.

 

[Lasse]

It looks like it does its work - limiting the lower pH:s

But - IMO - to take air from the skimmer is not a good idea. You miss one very important thing - you will not ad any oxygen to the tank through the skimmer if you recirculate the air into the the inlet. You will chemical remove CO2 when it pass the lime but you will not get any new fresh oxygen into the skimmer

Sincerely Lasse

 

[Joedubyk]

Fear not, ther's still a lot of things you can do to get pH bumps

 

[reefiniteasy]

I’ve been looking into adding a scrubber myself. As Lasse mentioned, disconnect the tube from the skimmer cup. All I’ve read said the input of the scrubber should be “open” and the output of the scrubber feeds the skimmer pump. Maybe try that instead of recycling the air.

 

[reefluvrr]

Is the air intake from your skimmer attached to your CO2 scrubber the right direction?
I believe I switched the direction of my phosban reactor such that the air is pulling from the bottom of my reactor and the exhaust is at the top part. I noticed my media lasting longer and my pH points also improving.

Another important difference for me was making sure my tubing from my skimmer to the co2 scrubber is a tight seal.
You could be pulling non-scrubbed air from the junction of the those tubing if the fit is loose.

HTH

 

[h2so4hurts]

Draw in from the outside. Recirculating has pretty mixed results for some people

 

[Lasse]

Recirculating has pretty mixed results for some people

To be honest - when I first saw the ideas of recirculation the skimmer air I thought that it was the worst idea for a long time. One of the most important issues for a skimmer is to oxygenate the water. This construction will not help with the oxygenation of the water at all

Sincerely Lasse

 

[X-37B]

Agree that you dont want to resirculate the skimmer air through the co2 scrubber.
This was my nano 25 gallon sump.
I dont have a pic of the scrubber but you can see where the air is going into the skimmer, the open orange line, that is where I attached a small bottle of soda pellets.
It worked well for a small tank but really ate up the media quick.
It pulls the air through the media and into the skimmer, thus filtering out the co2 allowing plenty of oxygenation.

 

[coastal_kid]

Tack Lasse.
I will experiment with non-recirculated air next.
This week I am experimenting with alkalinity. I forgot to test alkility before posting.
My alkalinity was 7.8 dKH.
I increased alkalinity to 10.6 dKH.
I will monitor the pH for a few days.

Then I will try scrubbing ambient air.
I'll report back in a week or two with the outcomes.

 

[h2so4hurts]

My alkalinity was 7.8 dKH.
I increased alkalinity to 10.6 dKH.

Whoa, in a day? You should never increase more than 0.5dkh per week. If you have sps you will likely kill them.

 

[coastal_kid]

Thank you reefluvvr.
I have the BRS CO2 scrubber.
I was too lazy to unscrew the media and check the connection, but the scrubber media is turning purple from the top down.
That indicates the air enters through the top of the media cartridge, passes through the media cartridge, and then exits the scrubber from the canister housing.

 

[coastal_kid]

Thanks h2so4hurts.
Oops. I'll see how the montis look today. If they look stressed, I'll drop the alk.
Maybe I'll have to change my screen name to SrCl2hurts?
This hobby really wants to teach me patience that I currently lack.
Last night I set up the dosing pump for alk. I will stop dosing manually.

 

[coastal_kid]

I use air from the skimmer cup to make the media last longer.
However, if the lack of oxygen prevents the equipment from doing its job, then there is not much point in saving on the media.

 

[h2so4hurts]

If you only have Monti's or birdsnest they will be fine. They're the Xenia of SPS.

 

[ca1ore]

A couple of thoughts. Using recirculating air for a skimmer is fine as long as you have adequate circulation in your tank. If you rely on the skimmer to be an important oxygenator (generally a bad system design IME) then obviously recirculating the air is NOT a good idea. Whether a fresh air line or CO scrubbing works is a function of CO2 balance between the water and the air. If you scrub the skimmer air of CO2, but your system is 'marinating' in high CO2 house air then the effect is likely to be marginal.

 

[Lasse]

If you rely on the skimmer to be an important oxygenator (generally a bad system design IME)

This i do not really understand because - IMO - the critical factor in order to oxygenate water from air is the area of contact between air and water - In the skimmer this contact area (if the air contain its 20 % oxygen) is much, much, much, much greater than an area you can create with waves on the surface. IMO - the skimmer is the most important instrument to either oxygenate the water (below 100 % saturation) or de-oxygenate the water (over 100 % saturation caused by photosynthesis) If you recirculate the skimmer air - it will be very oxygenrich during photosynthesis but it will be very low during time without photosynthesis.

However - in an other thread I saw a solution that maybe will work very well. The main air inlet to the scrubber was from the outside but there was a bypass from the skimmer cup that provide a little amount (but humid) air to the scrubber .

He also use two chambers - the first is old media and the second new media. When changing - he just place the old "new media" first and the new "new media" afterwards. This together with the humid air from the skimmer optimize the use of media - IMO

My Experience Raising pH

Any way you can draw up a simple diagram of this set up please You did say simple! I will try and knock something up on the computer when I get ba @Clownfishy any way you can draw up a simple diagram on what you have done here? Let me draw something up on the computer and post it but in the...

www.reef2reef.com

Sincerely Lasse

 

[KenO]

Having run a CO2 scrubber in AZ if you don’t provide it with moist air it will dry out. You could add a wye fitting and use some valves to pull moist air from the skimmer and inside air to provide fresh O2. I ended up pulling fresh moist air from my ATS.

Now with that said, is there a way to try running some tubing to the outside to pull in outside air? I’m in N Scottsdale and my outside air co2 measures 395-400ppm. My inside air co2 prior to installing a whole house air exchanger was in the 900+ppm range. With the air exchanger the co2 of the inside air is now below 500ppm.

I no longer run a CO2 scrubber, I found pulling in outside air worked better and is a whole lot less expensive.

 

[GK3]

Just add RO water to the bottom of the scrubber? Pretty sure BRS recommends this anyway.

 

[KenO]

Just add RO water to the bottom of the scrubber? Pretty sure BRS recommends this anyway.

In AZ with very low humidity levels the water at the bottom dries up quickly.

 

[Jeff Jarry reef]

Just add RO water to the bottom of the scrubber? Pretty sure BRS recommends this anyway.

They recommend one tablespoon.