Recirculating Co2 scrubber - amazing results

[legalizedreefer]

I’m still having an issue of skimmate being sucked into the bottom of the reactor from the recirc line, I installed a guard around the intake to try and block the foam and I increased my recirc line from about 8 inches to around 3 feet. Not sure how to mitigate this now

 

[Gill the 3rd]

I’m still having an issue of skimmate being sucked into the bottom of the reactor from the recirc line, I installed a guard around the intake to try and block the foam and I increased my recirc line from about 8 inches to around 3 feet. Not sure how to mitigate this now

Fish of Hex sells a kit to help avoid this. He 3D prints a skimmer up lid attachment and the recirc line goes into a cup before returning to the inlet of the reactor. That way any skimmate goes into the cup first.

Skimmer Scrubber Attachment

fishofhex.com

Edit: here's a picture of his setup

 

[Reef Stallion]

Fish of Hex sells a kit to help avoid this. He 3D prints a skimmer up lid attachment and the recirc line goes into a cup before returning to the inlet of the reactor. That way any skimmate goes into the cup first.

Skimmer Scrubber Attachment

fishofhex.com

Edit: here's a picture of his setup

I have this setup. I have my collector in the sump and hang the Phosban off the back of the tank so it quite high.

 

[Randy Holmes-Farley Verified Community Expert]

The oxygen thing is a theoretical I’ve seen mentioned several times but it seemed to be just that, a theoretical. I’ve yet to see anyone actually running in to any kind of problems in terms of tanking oxygen. Furthermore, one of my buddies has an oxygen sensor on his system and didn’t register any impactful change after installing a recirculating skimmer.

The second part is a real concern though. If you watch the video I have about a 100cm run to my canisters which elucidates most of that risk. However, a float switch in the skimmer cup would of course be ideal and something I’ll be adding in due time.

I think you may be dismissing a potential concern without much data.

Using your analogy, have you ever seen anyone run into "any kind of problems" from using a skimmer without a scrubber? No? If not, then why is a scrubber needed? Because you are trying to improve the aquarium conditions.

The fact that skimmers do sometimes add O2 (such as at night) is not theoretical. It's been measured and published. So in a full recirculating skimmer, where would the O2 come from?

How low can O2 get before you, as the aquarist, detect a visible change in the aquarium? Might there not be a situation where O2 is not optimal, but one does not observe gasping fish:?

Does one example of a tank not having a problem (your buddy) mean that NO tank can have a low O2 issue?

 

[Reef Stallion]

Here is my setup.

 

[Reef Stallion]

I think you may be dismissing a potential concern without much data.

Using your analogy, have you ever seen anyone run into "any kind of problems" from using a skimmer without a scrubber? No? If not, then why is a scrubber needed? Because you are trying to improve the aquarium conditions.

The fact that skimmers do sometimes add O2 (such as at night) is not theoretical. It's been measured and published. So in a full recirculating skimmer, where would the O2 come from?

How low can O2 get before you, as the aquarist, detect a visible change in the aquarium? Might there not be a situation where O2 is not optimal, but one does not observe gasping fish:?

Does one example of a tank not having a problem (your buddy) mean that NO tank can have a low O2 issue?

I’m confused. Are there studies showing that CO2 scrubbers lower oxygen levels in reef tanks? As far as I’ve seen, the media is designed with an affinity for CO2.
While the skimmer may potentially add oxygen, I never heard that a skimmer is essential for the health of the fish or to maintain oxygen in the tank. Over the years, I’ve run tanks successfully with and without them.
Looking at the percentage of oxygen verses CO2 in the air, oxygen makes up roughly 20% versus CO2 at 0.035%. I would think the high percentage of O2 is enough to easily overwhelm some small reductions by the recirculating skimmer but who knows.

 

[Randy Holmes-Farley Verified Community Expert]

I’m confused. Are there studies showing that CO2 scrubbers lower oxygen levels in reef tanks? As far as I’ve seen, the media is designed with an affinity for CO2.
While the skimmer may potentially add oxygen, I never heard that a skimmer is essential for the health of the fish or to maintain oxygen in the tank. Over the years, I’ve run tanks successfully with and without them.
Looking at the percentage of oxygen verses CO2 in the air, oxygen makes up roughly 20% versus CO2 at 0.035%. I would think the high percentage of O2 is enough to easily overwhelm some small reductions by the recirculating skimmer but who knows.

There are studies that show skimmers raise O2, especially at night, and a fully recirculating skimmer entirely loses this ability. The scrubber itself does not remove O2, it just prevents any new O2 from being added.

Some folks use partly recirculating and partly fresh air in a scrubbed skimmer for this reason.

 

[Slything]

My question for the concern with O2 levels of circulating is what about the people who have successful tanks with no skimmer at all?? If a skimmer was a requirement for O2 to stay at sufficient levels why can people go without one at all?

 

[Randy Holmes-Farley Verified Community Expert]

My question for the concern with O2 levels of circulating is what about the people who have successful tanks with no skimmer at all?? If a skimmer was a requirement for O2 to stay at sufficient levels why can people go without one at all?

They may or may not have low O2, just like a tank with a recirculating skimmer might or might not.

Skimmers help, but do not necessarily solve low O2 issues when they exist.

 

[Velcro]

Didn’t watch video but major issues here are lack of O2 saturation and potentially nuking tank if skimmer overflows. Keep both of these issues in mind when setting up these configurations.

Plenty of people have successful tanks with no skimmer at all and only the oxygen that is gained from surface agitation.

 

[piranhaman00]

Plenty of people have successful tanks with no skimmer at all and only the oxygen that is gained from surface agitation.

See post above. YMMV

 

[jda]

The other issue with recirculating skimmers is that even if you do raise other types of gas exchange to increase oxygen, you also mix in more high co2 air from the room - don't know how you get one without the other.

It makes sense to use a non-recirc scrubber to bring in o2, low co2 air and then not raise the gas exchange elsewhere if you don't have to.

 

[jdmquip]

I La looking into adding a CO2 scrubber also. Thanks for the video.