Programme neptune apex solenoid and ph meter to control co2 scrubber pipeline

al9903221 · Aug 15, 2023

Hi
I've got a tub of co2 absorbing media connected to my skimmer air intake... but if i leave it connected 24/7 the pH goes up to 8.5 in the daytime when the house is empty. So I want to put a neptune apex solenoid on my air tubing then a wye junction to a tube going to fresh air and a seperate tube going to the co2 scrubber.
Can you help me with the programming to have the solenoid shut the fresh air tube when the pH is below 8.25 so it draws air through the scubber media, and open it when the pH hits 8.4 so the air takes the path of least resistance from the open-ended tubing.
Hope that makes sense, or if you have a better idea I'd be grateful
Thanks

blaxsun · Aug 15, 2023

Sure (unless someone else has a similar setup and can just copy/paste the code for you). The Neptune solenoid is apparently always in the OFF position, if that helps. Feel free to PM me once you get everything and we can go from there.

A_Blind_Reefer · Aug 15, 2023

Aside from the program I don’t think the Neptune 1/4 inch solenoid is the best option, my lowly opinion. When I did this I found 3/8 inch high flow solenoids on eBay that were inexpensive, they were for drinking fountains I think. Most recommend full flow 3/8 inch ball valves but they are crazy expensive. My experience with the solenoids was that there was enough restriction that it would still draw from the scrubber. I ended up running two solenoids where one would open and the other close, to direct the flow accordingly. There is a great thread on here somewhere that I’ll try to find and link later if I remember

al9903221 · Aug 15, 2023

blaxsun said:
Sure (unless someone else has a similar setup and can just copy/paste the code for you). The Neptune solenoid is apparently always in the OFF position, if that helps. Feel free to PM me once you get everything and we can go from there.

Hi
I have everything ready. Just need the code. I suppose it will say that the solenoid is on (ie open) when the ph is 8.4 and off when its 8.25. When u say its always in the off position does that mean it will allow flow until its turned on or it is closed until its turned on?! My brain hurts

al9903221 · Aug 15, 2023

A_Blind_Reefer said:
Aside from the program I don’t think the Neptune 1/4 inch solenoid is the best option, my lowly opinion. When I did this I found 3/8 inch high flow solenoids on eBay that were inexpensive, they were for drinking fountains I think. Most recommend full flow 3/8 inch ball valves but they are crazy expensive. My experience with the solenoids was that there was enough restriction that it would still draw from the scrubber. I ended up running two solenoids where one would open and the other close, to direct the flow accordingly. There is a great thread on here somewhere that I’ll try to find and link later if I remember

Appreciate the info. Sadly ive already made the investment so i guess i will give it a try and get back to you when it fails!! You either win or you learn!

A_Blind_Reefer · Aug 15, 2023

al9903221 said:
Appreciate the info. Sadly ive already made the investment so i guess i will give it a try and get back to you when it fails!! You either win or you learn!

Ah, didn’t know you already had it as it said thinking about using. I don’t wish failure on anyone so fingers crossed it works out for you. I deleted my code when I upgraded last year, but if the solenoid is on the fresh air side, not the scrubber side I would do a fallback on, set on, if ph < whatever then off, defer 010:00 (or however long you want, just an example) then on. Just an example. There are other options. In this case you’re always drawing fresh air (even if the apex disconnects). You would only draw from the co2 scrubber when the ph is below your set point. The defer is so that the solenoid doesn’t cycle on and off rapidly if you’re right at your set point. I’m sure I messed up as I’m not with it any longer so always check yourself before you wreck yourself. Also, I’m sure someone will say I’m wrong and have a better idea so I’d go with that!