I did not think of it as fixing a problem, more adding a little more to the length of time and maybe a way for those with only one needle valve to prime and not change their setting. Also used the one day as an example to put some numbers to it. Numbers make more sense than letters to me.

How do you like the plastic bar "pro" kit? I was looking at that and the aluminum one and want to order something soon. I do have a 55g tank, but I am only looking for 2-2.5bps being my lights are medium. Not looking to get my plants growing crazy (Not yet) just want to add some carbon to help them keep the algae down. Working now with a 2 bottle yeast system and just wanted something a little better.

I like the plastic bar pro a lot. The needle valve is not great but works well enough. I did try a better needle valve for a few months and just used the unit valve as on and off. Went back to using just the unit valve during my last run.
You will have to adjust a few days a week anyway so I really don't see the advantage to the prime.

The way I see it if you prime it up front then you would get another day or 2 on the run instead of eating up your CA mix on day 1, it should not draw any over until the pressure drops from the prime. I guess I should have kept my mouth shut, made sense in my head.

The prime takes very little if the ca fluid. After the star it may be a couple of days before it draws more. Life of the mix varies. On my best tested mix I was getting on average three weeks at 2 bps for 8 hours a day. It would vary from two weeks to just over four.

IF you were going to do this all over, would you keep the plastic one or go with aluminum??

I don't know anything about the aluminum so I can't say for sure, but I was happy with the plastic. Hope that helps.

Ok, thanks. May pull the trigger tonight, just not sure on what one yet. Aluminum seems a better platform to mod later if I need to.

Hello there,
just a quick question, anybody tried this with 1l bottles? Or in theory, what would be the difference considering the standard recipe for 2l bottles? Twice the pressure with half the bottle volume? Industry standard pressure rating for 1l and 2l PET bottles is the same (150PSI, which is cca 10Bar).
The thing is, I have a verry little space for this and only can fit 1l bottles in the shelf..

Thanks!

Did not try it but don't see why not as long as you can accommodate the fluid volume and space for where the tube on the baking soda side vents into the bottle.

Ok, I can fit both mixtures in each 1l bottle (200g CA + 400ml water / 200g BS + 200ml water) and after the process ends, the BS bottle should contain cca 600ml of used mixture. Let's say the clearene for tubing is ok, is there anything else that could come in play? In theory, half the volume = twice the pressure, but if I start the mix with the correct pressure of 2Bar (with the initial squeezeing and shaking) it should be ok? Or am I missing something? I coulnd not find any information on smaller bottles with this setup, only 2l...

Sounds right. Not sure about double the pressure though. Chemistry or physics was never my thing.

In the setup I used to test dry baking soda with CA solution I did it with 1L bottles and the bottle caps. Max pressure wasn't an issue even though I ended up with a runaway reaction due to a leak at my needle valve.

Keep in mind that the reaction (i.e. amount of solution moving from Bottle A to Bottle B) should be controlled/throttled by the amount of gas flowing out through the needle valve and the resulting pressure differential between bottles A & B. As long as you can control the flow you should be able to maintain a fairly steady pressure much lower than the bursting pressure of the bottle. Theoretically you should be able to set the initial pressure via the priming squeezes and maintain it. Of course this is based on my experience. While I typically tried to run the DIY setup "in the green" on the gauge I've had my system operating at around 120 PSI without any failures.

I bought both the bottle caps from China on the 'bay and the aluminum setup from CO2Art before I decided to build my paintball setup. I don't have a plastic setup but I can't imagine that it would work any better or worse than the aluminum one. IMO the aluminum setup is easier to use (and safer) as it has a relief valve built in. The only thing I would change is to replace the needle valve with a better one.

120PSI is rather high for any soda bottle. I imagine that was just a peak and not a long term thing... So once you set up the pressure in the whole system, it should stay more/less the same, unelss you have a leak somewhere. And the pressure should be the same no matter the bottles volume. So base on your experience, my only worry should be if I can fit the solution in 1l bottle (considering the system works as it's supposed to). I orderd the D501 model, the same jrill has.

Hi. Apologies for jumping to the end. Is there a way to tweak yr formula to get less bubbles for longer time, with more stability. 0,5 bps is fine for 24/7. Want it to last for at least 3 weeks.

Using the needle valve you can slow down the reaction. No Citric Acid should move into the Baking Soda bottle unless the baking soda bottle pressure is lowered by opening needle valve.

I would also try more water in the Citric Acid side (Based on posts in this thread not on anything I actually did) to slow the reaction down some. Also make sure there are NO LEAKS or you will never get close to 3 weeks.

EDIT>> Make sure the volume of BOTH A+B is not bigger than one bottle. All the mix will end up in one bottle at the end. So when adding more water to the CA side of things make sure your not going to overflow the BS bottle.