AquaForest CO2 Scrubber Lowering pH?

[D.WhiteShark]

I have been struggling to get my pH consistently above 8.0.

For the last several months my pH would very consistently swing between 8.1 and 7.6 every day in almost a mirror image of the previous day. About a week ago I added an AquaForest Air Scrubber to see if I could bump it up just a tad in preparation of adding an anemone that I have in my other tank. After adding the scrubber, the degree of my pH swing is definitely better but now pH seems to be staying on the lower end of the swing. pH tops out at 7.8 and drops to 7.5 daily. Could I have done something wrong or do I just need to wait longer? Literally nothing has changed inside the tank, home routine or outside influence other than adding the scrubber.

-Innovative Marine Nuvo Fusion20 AIO set up about 6 months ago with live rock and sand from my 5yr established tank (averages 8.25-7.97).
-Fiji Cube HOB Refugium Large (mostly empty except of some LR rubble also from the other tank)
-2 small clowns
-1 small flasher wrasse



-Skimmer is Innovative Marine NuvoSkim AIO [Desktop]
-AquaForest Air Scrubber with a single Foam Pad and the Acrylic Defuser under the Media
-I’m using the JorVet Soda Lime that comes in the 5 gallon container from Amazon
-Media is filled about 1 inch from the top
-The length of hose was extended by maybe 5 or 6 inches to accommodate location of scrubber (I.D. is the same) no kinks, no significant rise or drop in hose.

 

[Randy Holmes-Farley]

I’m not familiar with the setup you have.

The air leaving the scrubber goes where?

 

[D.WhiteShark]

I’m not familiar with the setup you have.

The air leaving the scrubber goes where?

Air leaving the scrubber goes into the inlet hose of the protein skimmer.
Basically, I replaced the skimmer silencer with the CO2 scrubber.

 

[Randy Holmes-Farley]

Could be faulty media.

Could be the skimmer was already helping pull up pH, but the scrubber reduced the air flow and hence reduced the upward pull.

reducing the swing to just the lower end is a step backwards, IMO.

 

[D.WhiteShark]

I had no initial interest in reducing the swing, let alone to the lower end. I didn't think that adding the scrubber would in any way reduce the flow bringing the pH down since it's specifically designed to increase pH and so many other people are using them with positive results. I'll plan to follow up with another pH tester, calibrate my probe and maybe run my monthly parameter tests. Since the scrubber was the only change, anything else going on that would lower the pH would be a coincidence I think.

Would it be worth it to try a different media or am I better off with a stable but consistently lower pH that I had before?

 

[Randy Holmes-Farley]

I had no initial interest in reducing the swing, let alone to the lower end. I didn't think that adding the scrubber would in any way reduce the flow bringing the pH down since it's specifically designed to increase pH and so many other people are using them with positive results. I'll plan to follow up with another pH tester, calibrate my probe and maybe run my monthly parameter tests. Since the scrubber was the only change, anything else going on that would lower the pH would be a coincidence I think.

Would it be worth it to try a different media or am I better off with a stable but consistently lower pH that I had before?

It can’t really hurt to try different media since you will need to get more before long anyway.

 

[D.WhiteShark]

It can’t really hurt to try different media since you will need to get more before long anyway.

That was my thought too. In your experience is 7.6 - 8.1 reasonable long term? I am feeling like the 7.6 is too low as the bottom range

 

[Randy Holmes-Farley]

If the 7.6 is accurate, it concerns me.

 

[D.WhiteShark]

If the 7.6 is accurate, it concerns me.

That confirms my thoughts. I will check a few things and report back. Thanks as always for your help

 

[D.WhiteShark]

After a little tinkering I think I had a combination of small issues. None that contributed significantly by itself but together had the substantial impact.
I started with testing with another tester which showed the probe was not as acuate as it could have been (recalibrated probe).
Second, I read a few write-ups that indicated that having some moisture in the media could help with efficiency, I possibly added too much and had areas of clumped up media that dried out and became solid which stopped incoming air from passing through (switched out media and DID NOT add any water).
Third the Scrubber comes with an acrylic baffle that has multiple cut-outs for air to pass through. I realized the media could sit in those cut-outs and keep air from getting through. I also noticed it comes with several foam inserts and that two of them are a coarser foam than the others. I opted to put the acrylic baffle in first (all the way at the bottom) then use the coarse foam on top of it under the media to give incoming air the least obstructive path in and through the media.
Lastly, I repositioned my skimmer after I realized there should have been a lot more volume and fractalization (I don't know if that's the right word) of the air coming in.
Immediately after, I saw an increase in pH and over the last few days it has been consistently between 7.9 and 8.3 which I think should be right on the money for what I was expecting.