I guess I said plug and play is because I have no idea how to build it, and don't want to get it wrong. I do have a friend that manager of welding supply store, that can get me everything at cost. I do want something that high end, that will last a long time, I just don't even know where to being. :help:
Well that is half the battle. Get any 2 stage regulator that is set up for CO2 (CGA 320) inlet.( I once read there is no such thing as a bad 2 stage regulator..

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Only thing critical here is to make sure outlet pressure has a good range.. say 0-100psi.. Many CO2 injectors like 35psi or so to function properly
A tank that is the size you want..
Get a relay that, according to most here, has a low Watt draw.. (<8W or so???)
Get a timer to run the power for the solenoid
Get a very fine metering needle valve..
Tubing, bubble counter, check valve and some method of pumping the CO2 into the tank water (diffusion disc, in-line atomizer or reactor are the 3 choices)
Read this:
http://www.plantedtank.net/forums/showthread.php?t=148509
Doing all new and at cost will set you back, guessitmating, about $300
INSERT solenoid valve between regulator and needle valve
NOTE: reactor is only one option..
Create parts list w/ help from your welding person.. Check list here for advice on selections before ordering..
optional fun parts are pH controller to shut off the CO2 if pH starts to spike. (or maintain a range)
CO2 checker
ALSO try to make sure most of the parts fit together relatively easily.. i.e try to standardize fittings..actually a bit harder than it sounds... Ideally if everything was, say 1/4NPT you just wrench it all together..
When you cobble things togethr you get like mine.. 1/4NPT to 1/2 NPT back to 1/4NPT to 1/8 NPT to Hoke gyrolok to 1/8npt to 1/16 hose barb..
