DIY CO2

[Vardo]

Hi everyone, I was wondering if anyone has any experience with these or if anyone has any relevant advice about using and purchasing them? My CO2 kit was pinched when I moved house and I was wondering about using one of these but with a solenoid fitted to supply my nano set up.

 

[ian_m]

You cant use a solenoid with this type of setup as when the solenoid is off the pressure will continuously build up and either burst or leak the system.

What you do is use the solenoid to vent the bottles ie solenoid on a night letting pressure out the system. You just have to cope with yeasty smell when venting.

Or do what everyone else does, just run 24/7.

 

[Wookii]

You cant use a solenoid with this type of setup as when the solenoid is off the pressure will continuously build up and either burst or leak the system.

What you do is use the solenoid to vent the bottles ie solenoid on a night letting pressure out the system. You just have to cope with yeasty smell when venting.

Or do what everyone else does, just run 24/7.

Looks like the above system has a PRV on the side of it, so pressure build-up shouldn't be a problem. I also suspect is a citric acid based system, so no yeast. That said, it does seem an awful lot of faff when you can get get a soda stream canister for a similar price.

 

[alnitak]

Hello, IMO better use a sodastream or other real CO2 cylinder... Chemical reaction (and even yeast) cannot be monitored, and, as a chemist (sorry ), I do not recommend processes than cannot be controlled as easily as just opening or closing a solenoid.
No "chemical" hazard in case of overflow, but a real explosion hazard...

 

[Vardo]

You cant use a solenoid with this type of setup as when the solenoid is off the pressure will continuously build up and either burst or leak the system.

What you do is use the solenoid to vent the bottles ie solenoid on a night letting pressure out the system. You just have to cope with yeasty smell when venting.

Or do what everyone else does, just run 24/7.

Thanks everyone. I do know a solenoid will work with this set up also the whole system runs on fairly low pressure so it's unlikely to cause any leaking or over pressuring issues overnight , plus it has a safety release for excessive pressure just incase there is any build up but I appreciate the comments and concern.

As I don't have much option for anything else right now I was more looking for tips from people who have used them, I know they're becoming more popular. If I could afford to run a more traditional set up right now I would definitely but at the moment this is about the best I can do. The whole thing is around £40 with a solenoid and then roughly two years worth of citric acid and bicarbonate of soda is £20 on top of that.

 

[Vardo]

I finally got a CO2 set up like the one in my first post in the thread and it works a charm, I'm really impressed with it.
I'd definitely recommend one for anyone wanting a cheap CO2 set up, plus the reacting chemicals are dirt cheap, I got a 1kg bag of citric acid and a 1kg bag of baking soda off eBay for under a tenner.
The whole set up cost me £29 including chemicals.
I have it dialled in to 1 bubble every 4 seconds which seems to be plenty judging by the plants reaction and water parameters

 

[si walker]

Good on you.
Keep an eye on it though!
Hey update us on how long it lasts. Always good to know.
Si

 

[Vardo]

Good on you.
Keep an eye on it though!
Hey update us on how long it lasts. Always good to know.
Si

To be honest I wasn't that convinced it was going to be so effective but I'm pleasantly surprised how well it works. The pressure bounces back and forth between the bottles so citric acid is regularly drip fed using check valves into the bicarbonate of soda to create co2 , as the pressure drops in the bicarb bottle from feeding the tank the higher pressure in the acid bottle forces just enough acid up through the line into the bicarb bottle which in turn reacts and re-pressurises the whole system.

It's got a pressure release valve thank god, pretty sure it'd take out the tank if there wasn't anyway to prevent a runaway reaction 😄

 

[Vardo]

This diagram shows how it works, although this is a slightly different system the operation is the same

 

[ian_m]

This diagram shows how it works, although this is a slightly different system the operation is the same
View attachment 217338

You really ought to have a 3rd empty (or little bit of water) catch bottle before the tank just incase bottle A or B overflows. Any of bottle A or B entering the tank will kill all in the tank.

 

[Calamardo Tentaculos]

@Vardo Looks interesting! Do you mind PM-ing me the link to where you bought this and the ingredients from?

 

[Vardo]

You really ought to have a 3rd empty (or little bit of water) catch bottle before the tank just incase bottle A or B overflows. Any of bottle A or B entering the tank will kill all in the tank.

I get where you're coming from and I appreciate the concern but it can't happen, it's not like a yeast reactor set up. I've done plenty of them and have that set up down to an art, in my opinion yeast set ups are too unpredictable anyway. Regardless, there are multiple check valves and a high pressure release valve that stop that happening but it's not possible with the setup. Worst that can happen is it dumps all the co2 that's pressurising the system but that would require the needle valve to fail catastrophically and that would result in pressure releasing directly out the needle valve anyway.
The physics behind the set up prevent it from bubbling over basically.

 

[Vardo]

Ps the diagram isn't the exact set up I have, it's just a proof of concept to try to explain how the system works

 

[Vardo]