Adjustable pressure CO2 regulator anyone ?

[milk_vanilla]

i never seen this type sell on Local LFS, but could be purchased over ebay, etc.

Anyone use this adjustable solenoid model ?

i wonder what's the benefit other than if we need higher pressure to work in conjunction with co2 atomizer, etc.

[li_gangyi]

2 stage pressure regulators can give a more constant pressure over the entire life of the CO2 tank, single stage regulators tend to drift around especially when the tank is very low/almost empty.

Most pressure regulators you buy over Ebay aren't specifically made for aquarium use, thus they have an adjustable output pressure (for whatever the end user wants to dial it to). Aquarium use wise, unless you specifically need a higher pressure for your difuser/atomiser, it's better to leave it at a pressure that will just break through your difuser, you then get better adjustability with the needle valve. If you leave the pressure high, a slight turn of the needle valve results in a big change in the CO2 output, making it difficult to adjust the rate CO2 is being injected.

[tawauboy]

bioplast CO2 regulator has a knob for adjusting output pressure. no additional benefit other than ability to adjust output pressure.
pressure change when cylinder pressure is low aka "end of tank dump'' can be mitigated by having a needle valve.

[li_gangyi]

pressure change when cylinder pressure is low aka "end of tank dump'' can be mitigated by having a needle valve.

You've got to have a needle valve no matter if you've a single stage or dual stage regulator. I daresay most if not all single stage regulators will drift in output pressure as the tank pressure drops.