On my reefing journey, I found Kalkwasse + Skimmer + CO2 Scrubber to be very effective for bringing my pH from 7.8 - 7.9 to 8.26 - 8.36.
I guess most people would just leave it at that. However, I wanted to be more efficient with the CO2 scrubbing material so I wanted to implement a recirculating CO2 scrubber and control the airflow through the media to the skimmer. So I upgraded to an Aeraqua Duo.
Please note, I am not really looking to use my skimmer for filtration. So the question is how to tune this for efficient pH control.
My basic understanding of skimmers (which may or may not be true):
1. Foam head needs to break at or above the collar (base of the cup)
2. For wetter skimmate raise the foam head
3. Needle wheel venturi generally perform best when air is appropriately restricted to the pump as this actually increases pump speed and air draw.
Controls on the skimmer:
1. Exit gate valve - closing the gate raises the water level in the skimmer
2. Pump speed - increases water and air draw
3. Left-right external/recirculation control - pulls mix of internal and external water
I added the following controls:
1. An air solenoid valve that can switch between CO2 scrubbed air and house rich CO2 air
2. An inline shut-off valve that I can manually adjust to restrict airflow (not sure this is needed because of #2 above)
So how do we optimize this for pH control? There are so many dials to adjust.
A couple of thoughts:
1. Setting it to DC motor speed to 100% maximizes air-water mixture and should maximize pH impact
2. Maximizing recirculation would then produce higher pH water exiting the skimmer
3. Minimizing recirculation would move more tank water through the skimmer
4. Would running the DC motor at 50% with some recirculation be better and help not over skim the tank
5. The air solenoid is set to maintain the pH at 8.35 with a .05 hysteresis
6. I'm not sure I need an airflow restricted with the DC pumps
7. I don't think 2 & 3 make much difference
8. I think I may be better off shutting off the skimmer instead of switching to unscrubbed air which will drive pH down
Thoughts?
I guess most people would just leave it at that. However, I wanted to be more efficient with the CO2 scrubbing material so I wanted to implement a recirculating CO2 scrubber and control the airflow through the media to the skimmer. So I upgraded to an Aeraqua Duo.
Please note, I am not really looking to use my skimmer for filtration. So the question is how to tune this for efficient pH control.
My basic understanding of skimmers (which may or may not be true):
1. Foam head needs to break at or above the collar (base of the cup)
2. For wetter skimmate raise the foam head
3. Needle wheel venturi generally perform best when air is appropriately restricted to the pump as this actually increases pump speed and air draw.
Controls on the skimmer:
1. Exit gate valve - closing the gate raises the water level in the skimmer
2. Pump speed - increases water and air draw
3. Left-right external/recirculation control - pulls mix of internal and external water
I added the following controls:
1. An air solenoid valve that can switch between CO2 scrubbed air and house rich CO2 air
2. An inline shut-off valve that I can manually adjust to restrict airflow (not sure this is needed because of #2 above)
So how do we optimize this for pH control? There are so many dials to adjust.
A couple of thoughts:
1. Setting it to DC motor speed to 100% maximizes air-water mixture and should maximize pH impact
2. Maximizing recirculation would then produce higher pH water exiting the skimmer
3. Minimizing recirculation would move more tank water through the skimmer
4. Would running the DC motor at 50% with some recirculation be better and help not over skim the tank
5. The air solenoid is set to maintain the pH at 8.35 with a .05 hysteresis
6. I'm not sure I need an airflow restricted with the DC pumps
7. I don't think 2 & 3 make much difference
8. I think I may be better off shutting off the skimmer instead of switching to unscrubbed air which will drive pH down
Thoughts?
Last edited: