SMALL CO2 SYSTEMS/BOTTLES (MAYBE REFILLING)

PARAGUAY

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A 600g disposable would last quite a while on a tank that size. I can see the problem Andrew though yo want something that looks ok as its visible Not easy
 

Andrew Butler

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A 600g disposable would last quite a while on a tank that size. I can see the problem Andrew though yo want something that looks ok as its visible Not easy
A part is also something I can then use when I move up a size, which might be happening sooner now and using the system on that as I can get the Ista bottles refilled cheaper or any CGA320 bottle infact.
I normally want the impossible! :rolleyes:
 

ian_m

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So as I'm now a bit in the wind, what defines a dual stage regulator?
Dual gauge regulators have two pressure gauges, one is cylinder pressure and other output pressure. The cylinder pressure, for CO2, will always typically read 800psi/55bar as long as there is liquid CO2 in the cylinder. The output pressure gauge typically will read to 5 bar (70psi), typically 2.5bar is OK for CO2 injection. This may or may not be adjustable depending on your regulator, mine is fixed at 2.5bar and I have never had any issues injecting CO2.

To reduce the cylinder pressure from 800psi to say 35psi this can be done in a single stage or dual stage regulator. Dual stage generally reduces the 800psi to say 100psi where a 2nd stage reduces it to 35psi. Advantage of dual stage is better regulation, as cylinder pressure falls (ie when tank is empty and all liquid CO2 has gone) the regulator maintains the output pressure better than a single stage. To be honest, once cylinder pressure is falling, the cylinder is empty so you only have a day or two left anyway and as it maintains pressure you won't get any change in CO2 bubble rate to indicate the cylinder is getting empty. Dual stage is obviously more expensive.

Single stage uses a single regulator to reduce 800psi to 35psi in one go. Has the advantage of being cheaper. Also has an advantage (though dual stage users disagree) that as cylinder pressure departs from 800psi, as liquid CO2 has all gone, the final output pressure can fall as well. This is a really handy indication that CO2 is running low and the tank needs changing. One disadvantage of some single stage regulators is that they can suffer end of tank dump, where are when the cylinder pressure falls to say 400psi the regulator loses all regulation and empties the CO2 cylinder in one go. If the tank is small this will asphyxiate the fish, but if the tank is large won't make much difference, but is reckoned to generally a bad thing. My single stage CO2Supermarket regulator does not end of tank dump, the CO2 injection rate just gets slower and slower as cylinder pressure falls until at about 200psi (after many days) it stops altogether.
 

Andrew Butler

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Thanks @ian_m
I understood (in a fashion) the difference but unsure there is a way to tell for sure without having things apart is there?
I will guess that it's just a dual gauge and not dual stage and assume 'tank dump' is something I would only find out through trial.

Time to toss a coin, return as (probably) misinformed or stick with the Ista.
 

Nick potts

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Thanks @ian_m
I understood (in a fashion) the difference but unsure there is a way to tell for sure without having things apart is there?
I will guess that it's just a dual gauge and not dual stage and assume 'tank dump' is something I would only find out through trial.

Time to toss a coin, return as (probably) misinformed or stick with the Ista.
While dual stage is always going to be preferred for the reasons mentioned above, a single stage reg is usually going to be perfectly fine for aquarium use, there are a lot in use.

If you want to keep the insta reg, you could pick up an adapter to convert it to DIN 477 so your options with bottles aren't so limited.
 

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