co2 scrubber

[Randy Holmes-Farley Verified Community Expert]

My skimmer often gets too active to consider recirculating the air from that source. Too much of a chance of sucking up some skimmate.

I've been pondering adding another inline canister (the same configuration as the scrubber) which contains a water source and maybe a piece of foam to help wick the moisture. So, outside air would first go through the "moisture chamber" and then into the scrubber.

That is a good plan.

 

[sbazain]

am recirculating right now having no problem with skim mate or moisture lets see how long it lasts now skimmer is working awesome didn't have to do anything to the setting

 

[sbazain]

well at first it was at 7.6 added scrubber went up to 7.9 after seeing how fast the media was getting depleted with was three days made it recirculating and nd now am up to six days not depleted yet but now my ph is raising to 8.5 today I added a liner out side air in the room with valve if I open it a bit can I control the ph

 

[sergifed91]

Here's my setup. Skimmer to one media reactor that is partially filled. Then that to my co2 scrubber then to my skimmmer.

 

[Reefahholic]

It is somewhat disappointing to me that folks like BRS who are pushing this practice appear to have not considered all of the ramifications of recirculating the skimmer air before recommending it. They should at least mention the theoretical concern, if not measure it, before advising folks to do it.

Skimmers have been shown to oxygenate the water of reef tanks, which often become less than saturated with O2 at night. By aerating with air that has normal oxygen levels, the skimmer can raise those levels. Eric Borneman showed this in his O2 studies.

If a skimmer is no longer getting fresh air, but only air that is already in O2 equilibrium with the water (as recirculating air will be) it can no longer increase the O2 level in the water.

Is this a big problem in most tanks? Probably not. But it is a drawback that is being ignored.

I wonder if we could measure this just to understand what the difference in oxygen would be between the two. Is it huge, or just a minor issue. Sigh...gotta love Reefing!

 

[Reefahholic]

The skimmer cup mixing does not provide water aeration, rather an opportunity for the recirculated and open air to replenish the oxygen. This is what makes it an open versus closed system. In a closed system it could certainly strip the oxygen reducing the diffusion potential.

If the air starts at 210k ppm oxygen, goes through the skimmer (gas exchange etc) then comes out the top...we will likely not see substantial oxygen depletion of the recirculated air in a short period of time that is not compensated by the small fresh air exchange in the skimmer cup (saturation being 7 ppm... with fraction of a ppm exchange rates).

Just to clarify. The room air that we breathe in or that a skimmer would draw is 21% pph (parts per hundred). The 210 that your referring to above is 210 ppm (parts per million) not thousand.

The difference between pph (%) and ppm is a factor of 10,000.

 

[Reefahholic]

Addition of fresh air into the loop certainly help, yes.

Think if you bleed-in 100% oxygen.

 

[Reefahholic]

I can honestly say my CO2 scrubber was by far the most effective way to increase pH w/o dosing a lot of Lime Water.

However, who knows what it was doing to the overall tank oxygenation and changing the media gets old.

I can say my tank was growing very well before I shut it down after I caught COVID. So it must not have been affected too much.

 

[Reefahholic]

The only thing I’d do different is to install a water trap drain between the first canister intake and skimmer cup to prevent condensation buildup in the first and second canisters. You’d have to modify or find one that fits the tubing your running. Typically, this was not much water buildup (more in first canister), but is annoying to drain and will also exhaust the bottom of your media if ignored. Finding a balance is difficult unless your drew air from a closed section of the sump.

 

[Ls7corvete]

You guys might want to try and find some rebreather divers that use Sofnolime, generally they are only using up about half the capacity of the lime. They would probably sell the partially used stuff for a fraction of what you would pay.

 

[Jon's Reef]

Just to clarify. The room air that we breathe in or that a skimmer would draw is 21% pph (parts per hundred). The 210 that your referring to above is 210 ppm (parts per million) not thousand.

The difference between pph (%) and ppm is a factor of 10,000.

Air is 21% oxygen
21% = 21 pph
21 pph x 10,000 = 210k ppm

Also, see https://en.wikipedia.org/wiki/Atmosphere_of_Earth

 

[SPS2020]

Here's my setup. Skimmer to one media reactor that is partially filled. Then that to my co2 scrubber then to my skimmmer.

That is very similar to what I was thinking. I like your idea of a safety net just in case.