Solenoid to control CO2 scrubber

FGourdin · Oct 4, 2021

I am thinking of installing an Apex ph controlled CO2 scrubber. CO2 levels in my "tight" house are around 1300 ppm versus 500 outdoors. For logistics reasons can't run current skimmer air intake outdoors. pH in tank 7.8 with Alk= 8.0 Has anyone had experience with a solenoid controlled air intake where valve would open to scrubber say with a ph less than 8.3 and draw room air for ph over 8.3? Can you give some details as to setting it up? Solenoid part number? ( I have looked at the Carr McMaster catalog and find it overwhelming- their customer service won't advise on specific applications!). Any help greatly appreciated.

lapin · Oct 4, 2021

FGourdin said:
Valve would open to scrubber say with a ph less than 8.3 and draw room air for ph over 8.3?

A solenoid is either normally open or normally closed.
To me you want it to have 2 intakes it can switch between. I dont of one that does this.
You could use 2 solenoids connected to a "Y"
They would be normally closed.
120v that would be plugged into an apex or power bar.
You will need a Ph sensor.
The apex would open the one (to scrubber) if the PH is less than 8.3
The apex would open the other one (room air) if PH is greater than 8.3

Does this sound like what you want?

FGourdin · Oct 4, 2021

lapin said:
A solenoid is either normally open or normally closed.
To me you want it to have 2 intakes it can switch between. I dont of one that does this.
You could use 2 solenoids connected to a "Y"
They would be normally closed.
120v that would be plugged into an apex or power bar.
You will need a Ph sensor.
The apex would open the one (to scrubber) if the PH is less than 8.3
The apex would open the other one (room air) if PH is greater than 8.3

Does this sound like what you want?

Yes, this sounds quite practical. Have noticed that others are using motorized ball valves instead of solenoids, because they don 't have to be energized accept for the actual 3-5 second opening sequence. Thanks for your input.

fdevans · Dec 30, 2021

I ordered one of these and one of the 24 volt 1-link cables since I didn’t want to waste a full outlet on it. I haven’t had time to install it yet, but the price was pretty good. I don’t think you need two though. If the room air has less restriction than the scrubber it should just require opening and closing that one. Keep the room air tubes shorter than the scrubber air and should be good.

There is a video somewhere that I saw the same idea / plan. If I can find it again ill

((FORDTECH)) · Dec 30, 2021

fdevans said:
I ordered one of these and one of the 24 volt 1-link cables since I didn’t want to waste a full outlet on it. I haven’t had time to install it yet, but the price was pretty good. I don’t think you need two though. If the room air has less restriction than the scrubber it should just require opening and closing that one. Keep the room air tubes shorter than the scrubber air and should be good.

There is a video somewhere that I saw the same idea / plan. If I can find it again ill

If you don’t close off the room air line when the CO2 scrubber line is open it will still pull the air from the room instead of through the scrubber so you need 2 solenoids and yes the solenoid you suggested works great I have four of them for my large skimmer that has two air in take lines so two solenoids Per line

fdevans · Dec 30, 2021

Found the video. Few things I would do differently but it gave me the idea:

The valve I linked can be wired as “Normally Closed”. So you only need 1. When the 1-link line is powered it will open, when the power is turned off it closes again.

fdevans · Dec 30, 2021

* correction
It’s not a 1-link cable. Just a 24 volt bare wire from Neptune. (Only has two prongs and bare red/black wires)

DeputyDog95 · Mar 8, 2023

Are ball valves still the way to go over the solenoids?

Any downsides to using the electronic ball valve?

((FORDTECH)) · Mar 8, 2023

DeputyDog95 said:
Are ball valves still the way to go over the solenoids?

Any downsides to using the electronic ball valve?

If you had a manual valve, you would not be able to automatically control anything obviously so the downfall is with the manual valve not with a solenoid valve

DeputyDog95 · Mar 15, 2023

((FORDTECH)) said:
If you had a manual valve, you would not be able to automatically control anything obviously so the downfall is with the manual valve not with a solenoid valve

I'm sorry... I did not phrase my question correctly.

Are the electronic ball valves preferred over the electronic solenoid valves at this point?

((FORDTECH)) · Mar 15, 2023

DeputyDog95 said:
I'm sorry... I did not phrase my question correctly.

Are the electronic ball valves preferred over the electronic solenoid valves at this point?

The reason why the electronic ball valve is better is because a ball valve when open or closed is either fully open or fully closed with no restriction where as the electronic solenoid valve is normally used on a pressure system, so the pressure can get past the resistance in the valve with a ball valve, you can blow through it like nothing but a solenoid valve. There is resistance with all that being said you want the ball valve so the Aircon more easily be sucked through it. With a solenoid valve, it would be hard to use for a gravity, fed water, top off because of the resistance. The water would not get past it but the ball valve on the other hand when it’s open, there is no resistance.