CO2 scrubber plus skimmer vs. no scrubber or skimmer at all: what would lead to higher pH?

[Tim617]

I am trying to understand if a CO2 scrubber + skimmer would raise pH more compared to not using a skimmer in the first place. I plan to use an algae reactor and a filter rollermat, and from all the research I have done, that should make the skimmer essentially superfluous when it comes to nutrient export. Then, without a skimmer, I am not aerating the water with atmospheric CO2 in the first place, which has to be better than a scrubber/skimmer combo which is introducing less but at least some atmospheric CO2 into the water.

Am I correct in this conclusion?

Now, a recirculating skimmer would likely raise the pH more, as it will get rid of some of the CO2 absorbed into the water through surface gas exchange from turbulence. But that is a DIY and I won't do it because of the risk of failure.

This is why I am asking: the place where I plan to keep the tank will be a high CO2 area, because of other natural gas burning equipment close by, but also because it's the lowest level of the house and CO2 is heavier than air so will have a higher concentration there. So I may have pH issues and may need a solution (to be seen, but I am in the planning phase now).

I really don't want to have a skimmer if it is not needed for nutrient export (and save the cleaning). I read that someone else constructed a supercharged scrubber with air pumps and diffusers, which worked great so I can do that, but I suspect that will 1) lower salainity from salt creep, and 2) inject microbubbles in the display which is neither good to look at nor necessarily healthy for the fish. But I can't see how even that would be better (by the above logic) than not having a skimmer at all.

Thoughts most welcome, and thanks much in advance!

 

[I.AM.MR.MIKE]

Am I correct in this conclusion?

NO

 

[blaxsun]

I believe the skimmer+scrubber will yield the best results. Fresh air or an air exchange system will also help. While the skimmer does put oxygen into the water, there's enough surface area that will exchange with the surrounding air anyway.

 

[EeyoreIsMySpiritAnimal]

I am trying to understand if a CO2 scrubber + skimmer would raise pH more compared to not using a skimmer in the first place. I plan to use an algae reactor and a filter rollermat, and from all the research I have done, that should make the skimmer essentially superfluous when it comes to nutrient export. Then, without a skimmer, I am not aerating the water with atmospheric CO2 in the first place, which has to be better than a scrubber/skimmer combo which is introducing less but at least some atmospheric CO2 into the water.

Am I correct in this conclusion?

Now, a recirculating skimmer would likely raise the pH more, as it will get rid of some of the CO2 absorbed into the water through surface gas exchange from turbulence. But that is a DIY and I won't do it because of the risk of failure.

This is why I am asking: the place where I plan to keep the tank will be a high CO2 area, because of other natural gas burning equipment close by, but also because it's the lowest level of the house and CO2 is heavier than air so will have a higher concentration there. So I may have pH issues and may need a solution (to be seen, but I am in the planning phase now).

I really don't want to have a skimmer if it is not needed for nutrient export (and save the cleaning). I read that someone else constructed a supercharged scrubber with air pumps and diffusers, which worked great so I can do that, but I suspect that will 1) lower salainity from salt creep, and 2) inject microbubbles in the display which is neither good to look at nor necessarily healthy for the fish. But I can't see how even that would be better (by the above logic) than not having a skimmer at all.

Thoughts most welcome, and thanks much in advance!

Both pieces of equipment will add O2.

 

[Tim617]

I believe the skimmer+scrubber will yield the best results. Fresh air or an air exchange system will also help. While the skimmer does put oxygen into the water, there's enough surface area that will exchange with the surrounding air anyway.

Help me understand it though. No skimmer scenario is putting no O2 or CO2 in the water. Scrubber plus skimmer scenario is putting O2 and some CO2 in. O2 and CO2 absorbed by surface exchange is unchanged in both scenarios. So am I not better off having no skimmer at all, comparatively speaking?

If push comes to shove I will get a skimmer, but I am trying to understand the logic here. Thank you!

 

[Tim617]

Both pieces of equipment will add O2.

I agree, but O2 is pH neutral. So that shouldn't matter, right?

Otherwise I could simply get an O2 concentrator and pump that in with a diffuser. But how would that lower pH? It will increase oxygen saturation, of course, in the water.

 

[blaxsun]

Let's back up a bit... What's your pH?

 

[Tim617]

Let's back up a bit... What's your pH?

I am designing the setup now. So no tank, yet. Build starts in 3/1 and will be hopefully completed by 4/1. Being an engineer by training, I am doing a detailed planning and design on equipment and setup, and the project timeline, including when to add what to the tank.

The old tank that sat in the same place used to have 7.5-8.0 or so, and I didn't have a skimmer on it. But it was exclusively a soft coral tank. So pH mattered less.

 

[mdb_talon]

I am not aerating the water with atmospheric CO2 in the first place, which has to be better than a scrubber/skimmer combo which is introducing less but at least some atmospheric CO2 into the water.

This may or may not be accurate. Many processes in your tanks create co2 and aeration can help eliminate that co2. However it can go the other way and the tank is low in co2 and increasing aeration may just increase the co2 concentration in the tank. Limiting aeration in my mind just means your co2 levels(and ph) are going to be driven more by the internal processes in the aquarium.

Personally i always would prefer to have my tank as aerated as possible in any case. While o2 does not impact PH it is important ...

 

[blaxsun]

There's an associated monthly cost with a scrubber, so if that's not an issue I'd work a scrubber into the layout and configuration so you have the option later.

 

[EeyoreIsMySpiritAnimal]

I agree, but O2 is pH neutral. So that shouldn't matter, right?

Otherwise I could simply get an O2 concentrator and pump that in with a diffuser. But how would that lower pH? It will increase oxygen saturation, of course, in the water.

I guess I was factoring in improved gas exchange. But, as is stated in another post, this can go both ways... For my tank, I see increased pH when the skimmer is on.

 

[Tim617]

This may or may not be accurate. Many processes in your tanks create co2 and aeration can help eliminate that co2. However it can go the other way and the tank is low in co2 and increasing aeration may just increase the co2 concentration in the tank. Limiting aeration in my mind just means your co2 levels(and ph) are going to be driven more by the internal processes in the aquarium.

Personally i always would prefer to have my tank as aerated as possible in any case. While o2 does not impact PH it is important ...

That is fair. What do you think of the supercharged scrubber idea used without a skimmer? See link:

I can peg my pH at 8.3 but it costs $2/ day. Is this worth it?

I've tried a variety of CO2 scrubbing setups and had some success, but the cost of media is giving me pause. Short story is: right now my tank pH is pretty low. Basically 7.8 - 8.0 if I just left it as-is (no CO2 scrubber). It was much better in summer and fall so I think this is because the...

www.reef2reef.com

It's very attractive (look at that rock steady graph of pH!) but I am afraid of salt creep and microbubbles from the diffuser. Any thoughts there? I still don't understand how it works though. DO should have no impact on pH.

Does Dissolved Oxygen Affect pH? | Atlas Scientific

Dissolved oxygen does not directly affect pH levels because there is no physical-chemical connection between the two. However, in some cases there are indirect relationships from external factors…

atlas-scientific.com

 

[Tim617]

There's an associated monthly cost with a scrubber, so if that's not an issue I'd work a scrubber into the layout and configuration so you have the option later.

Any thoughts on this setup?

I can peg my pH at 8.3 but it costs $2/ day. Is this worth it?

I've tried a variety of CO2 scrubbing setups and had some success, but the cost of media is giving me pause. Short story is: right now my tank pH is pretty low. Basically 7.8 - 8.0 if I just left it as-is (no CO2 scrubber). It was much better in summer and fall so I think this is because the...

www.reef2reef.com

Any risks of salt creep and loss of salinity, or microbubbles? I can easily fit this in to my schema.

Really, AIOs give you so little flexibility in space! <sighs>

 

[blaxsun]

Really, AIOs give you so little flexibility in space! <sighs>

Is this for an AIO tank?

 

[Tim617]

Is this for an AIO tank?

Yes, I have settled on a Red Sea Reefer.

 

[blaxsun]

Yes, I have settled on a Red Sea Reefer.

What model? AIO typically means no external sump.

 

[Tim617]

What model? AIO typically means no external sump.

Oh. sorry then. This will have a sump. Reefer 350.

 

[mdb_talon]

That is fair. What do you think of the supercharged scrubber idea used without a skimmer? See link:

I may not be understanding or maybe missing something but i dont see the point of a supercharged scrubber without the skimmer. I mean i understand if you just dont want the skimmer removing too much doc or trace elements but in that case i would use a skimmer without the cup(or leave the cup on and have a bottom drain on the cup always open to more effectively manage bubbles)

I guess you could build a super co2 scrubber without a skimmer body, but it seems like a skimmer is already designed to do most of what you need.... a container to inject air and have a lot of air contact with water while also containing those millions of microbubbles and preventing salt creep.

 

[HuduVudu]

If your room/house CO2 is not near atmospheric levels then it doesn't matter because you will need to either pipe in outside air or deal with the room/house CO2.

FYI O2 is not the issue when dealing with gas exchange. You will have enough, but CO2 on the other hand will be too high. You die in a sealed room from elvated CO2 not depleted O2.

 

[Tim617]

Actually, Randy Holmes-Farly already answered my question in 2018.

Use of a skimmer as only a gas exchanger eqiupment

Since i start my new aquaria (see my build thread) I have use my skimmer only for gas exchange and run it with very, very low production of skimate. It has worked as it should with keeping my pH between 8,1 - 8.4 However - since yesterday I started to add living planktonic phytobacteria to my...

www.reef2reef.com

Without a skimmer, pH will be higher, but DO will fluctuate like crazy. Which, of course, is not good. So I have to make room for a skimmer. And if I am getting one, I have to get a scrubber as well.

Oh well.