Solenoid valve for CO2 control

[dc88]

Anyone know where to find solenoid valve that is normally-open type ? Want to use it to control DIY CO2 so to vent it at night (syn with the light switching).

[PeterGwee]

Anyone know where to find solenoid valve that is normally-open type ? Want to use it to control DIY CO2 so to vent it at night (syn with the light switching).

Use an air-pump on timer instead would be a cheaper option. If you really want to go the solenoid way, you might as well get a gas tank system.

Regards
Peter Gwee

[dc88]

Hi Peter

Air pump at night would be noisy though.
How much you think such solenoid would cost ?

[PeterGwee]

Hi Peter

Air pump at night would be noisy though.
How much you think such solenoid would cost ?

A powerhead near the surface would do the same job as an airpump if noise is an issue since increase surface movement would help degas off the "excess" CO2. I'm not sure about the source for the normally open solenoid since I have never purchase one.

You can also consider using the powerhead as a CO2 injector by feeding the CO2 into the inlet (just make sure the DIY CO2 bottle is rigid). Place the powerhead with the inlet facing the water surface and place it somewhere near the top so that the CO2 would escape very fast once the powerhead is off (You can "off" the CO2 at night by using this method).

Regards
Peter Gwee

[dc88]

Thanks Peter,

I found one source selling such solenoid at about S$70+.

I will try the powerhead method. I think this is the "Tom's DIY Internal CO2 reactor w/venturi" method ?
I went to the details at his website I think the venturi and Burp-tube are simply genius invention !

[PeterGwee]

Thanks Peter,

I found one source selling such solenoid at about S$70+.

I will try the powerhead method. I think this is the "Tom's DIY Internal CO2 reactor w/venturi" method ?
I went to the details at his website I think the venturi and Burp-tube are simply genius invention !

Its not the venturi style reactor but just a simple mist injector method by injecting the CO2 into the impeller of the powerhead when the light is "on" only. Since the placement of the CO2 inlet is near the water surface, it escapes readily once the powerhead is "off" and does not cause the CO2 to buildup as I found with the venturi reactor since it acts like a bell reactor even without any flow from the powerhead.

Regards
Peter Gwee

[dc88]

... I found with the venturi reactor since it acts like a bell reactor even without any flow from the powerhead....

That was why he added the Burp-tube in his design so to allow the builtup to escape at night.

Anyway I will give your idea a trial !

This is actually for a new 1.5 ft tank I am adding to my tanks collection. DIY CO2 should be adequate.

Question : If I use only one powerhead to drive the CO2 and for moving the water around (without any more filtering device), and off the power head at night will that cause any problem at night as there will be no water movement ? I don't plan to add additional filtering device or second power head as the tank is small and don't want to add more heat source to it.