Several years ago, I had a CO2 regulator from Carbon Doser / Aquarium Plants which has the unique feature of a "regulated" bubbles per second instead of a needle valve. Due to a depleted tank and back pressure from my reactor, it died a salt-watery death, or at least the main value portion - the "doser" part.
I took it apart at that time, and discovered its basically made up of three main parts:
- A Clippard solenoid valve (this is what ended up being plugged due to salt water intrusion, stupid check valves)
- An off the shelf "timer" module
- A potentiometer
Basically nothing for the $200 upcharge compared to the cheap CO2 regulator included. The timer module basically pulsed the solenoid valve on for ~ 100ms at a time.
A couple of years ago I made a quick circuit using a 555 timer to run the Clippard valve:
It was an easy to build design using all through hole parts.
The original PCB design was:
https://oshpark.com/shared_projects/kJ0Pkzaz
https://octopart.com/bom-tool/KsaVM9dL
I've been using one of these for awhile now, but want to improve the design combined with Reef-Pi and a closed loop setup using a pH probe. I'm still powering some things from an APEX Classic ( which died a total death and had to be repaired here: https://www.reef2reef.com/threads/fixing-a-broken-apex-classic-main-unit.366496/ ) and turning power using a main solenoid valve on and off based on the pH from that unit.
The above is totally usable, but look for some updates here for the Reef-Pi version.
I took it apart at that time, and discovered its basically made up of three main parts:
- A Clippard solenoid valve (this is what ended up being plugged due to salt water intrusion, stupid check valves)
- An off the shelf "timer" module
- A potentiometer
Basically nothing for the $200 upcharge compared to the cheap CO2 regulator included. The timer module basically pulsed the solenoid valve on for ~ 100ms at a time.
A couple of years ago I made a quick circuit using a 555 timer to run the Clippard valve:
It was an easy to build design using all through hole parts.
The original PCB design was:
https://oshpark.com/shared_projects/kJ0Pkzaz
https://octopart.com/bom-tool/KsaVM9dL
I've been using one of these for awhile now, but want to improve the design combined with Reef-Pi and a closed loop setup using a pH probe. I'm still powering some things from an APEX Classic ( which died a total death and had to be repaired here: https://www.reef2reef.com/threads/fixing-a-broken-apex-classic-main-unit.366496/ ) and turning power using a main solenoid valve on and off based on the pH from that unit.
The above is totally usable, but look for some updates here for the Reef-Pi version.
