# CO2 tank Question about end of tank dump



## jbyoung00008 (May 16, 2011)

Ive read some post lately that said inpaticular the Co2 regulator I have from Milwakee is known to dump the rest of the Co2 bottle into the tank. Im wondering if some can shed some light on what exactly this means???? and proof of how you know this would be great too.

I just spoke to my cousin who owns a welding shop. Metaltropolis in Maple Ridge(free advertisement LOL) I had a hard time explaining to him what people were talking about when they say if you run the tank out it will dump ???? into the tank. The only thing he could think of was the fluid inside it could be dumped as the bottle runs out of gas but he said that would only happen if the bottle was upside down.

So I want to find out. Is this an old wives tale???? Does anyone actually have proof that this happens. Inpaticular to the Milwakee regulator Milwaukee CO2 Regulator with Needle Valve & Solenoid I have or to any Co2 regulator. When I say proof I mean actual proof not that you read it somewhere. What makes other regulators different?

If you have an opinion I would enjoy hearing it

Thanks in advance everyone!!!!


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## trout (Mar 21, 2012)

Took me awhile to understand eotd, but basically when the inlet pressure (bottle pressure) decreases, the working pressure can rise to more than what you have it set at "dumping" more co2 into the tank than desired. No I have no proof, just lots of research and reading horror stories. Granted it's one of the most common reg set ups for aquariums so an issue here or there is likely to be more widespread/known than other brands.

Look up rise/decay in regards to co2 pressure, might give you a better answer than my wording.

Quality of the components can differ one reg from the other in terms of being susceptible to eotd. Can be avoided by tweaking the working pressure as the bottle emptys, or gets refilled before it begins to happen. I'm no pro an could be way out in left field......so grain of salt here

Edit: I should add it's Not just milwakees in reference to eotd, a number of single stage regs can do it as well


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## jbyoung00008 (May 16, 2011)

trout said:


> Took me awhile to understand eotd, but basically when the inlet pressure (bottle pressure) decreases, the working pressure can rise to more than what you have it set at "dumping" more co2 into the tank than desired. No I have no proof, just lots of research and reading horror stories. Granted it's one of the most common reg set ups for aquariums so an issue here or there is likely to be more widespread/known than other brands.
> 
> Look up rise/decay in regards to co2 pressure, might give you a better answer than my wording.
> 
> Quality of the components can differ one reg from the other in terms of being susceptible to eotd. Can be avoided by tweaking the working pressure as the bottle emptys, or gets refilled before it begins to happen. I'm no pro an could be way out in left field......so grain of salt here


Thanks I will read up on what you are talking about.

My quick response is that I have a needle valve so how would more pressure over come the needle valve and dump un wanted co2 into the tank?


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## Bien Lim (Apr 21, 2010)

this is more detailed I guess!!!

The reg uses pressure from the tank working against a spring to hold the gas channel open for gas to flow. This is a very small gap with little variance. It is designed to work with the normal pressure coming from the tank to hold the opening steady but as the tank liquid gas is used up, the tank is left with gas only. This gas alone is not at as high pressure as normal when there is liquid present. At some point as the gas is used the pressure drops to a minimum point where the reg is not designed to control the flow. It still has gas but not enough to work in it's range so it lets the remaining gas gush out of the cylinder. Doesn't seem right but it does. Keep the gas cylinder from running down to this point and it doesn't happen. But that takes careful watching on the tank high pressure gauge. Once the needle begins to move, it can go down pretty quick. Refill before needed?


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## Bien Lim (Apr 21, 2010)

once the pressure in the tank becomes low your bubble counter should increase as well by it self, you can see this once the tank pressure gets to around 600psi (by this time you should keep an eye on it) the newly filled tank should say around 800psi (winter) to 900psi( in the summer ) and it will stay high like this for a while till the liquid runs out inside tha tank. You can always adjust you working pressure to say 10psi or lower till you get your bubble count down to your liking, I do this when I dont have time to get it refiled right away. Unfortunately, some regulator only comes Pre-set (20 psi) and does not allow you to adjust the working pressure. 

Ps,
And it does happened!! it happened to me but I caught it in time, lose some fish but not all. My friend wasn't as lucky as me!!

hope that helps


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## jbyoung00008 (May 16, 2011)

Thanks for all the input. Im still trying to understand how and why this happens. I have run my tank out before with no negative effects. Is this something that happens all the time or only when you have nice fish?? LOL 

Bien Lim thanks for the input on the pressures. I think my tank is just about empty I will turn down the psi until I have time to have it filled


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## 2wheelsx2 (Apr 21, 2010)

All single stage regulators have this problem, not just Milwaukee. The Milwaukee is a fine single stage regulator. Are there better ones, of course. Are there worse ones, of course. I've had one incident of EOTD which caused me to get a dual stage. But I never run any of the regulators down to nothing anyway, as there's not much savings in it. Once the tank pressure starts to drop, I run over to Royal City Fire Supply and am back with a full tank in 30 minutes. I only do this once a year as I have a 20 lb tank on my 125 gallon and a 10 lb on my 8 gallon ADA cube.

There are many websites with full explanations including diagrams explaining how and why single stage works and how it behaves relative to a dual stage as there are reasons why for medical use, one is better than the other. For instance, for medical use, I believe medical use, a dual stage is superior, while for things like welding, a single stage may be better or superior. A google search came up with this first result which shows the diagrams and explains it quite well. What is the difference between single-stage gas pressure regualtors and two-stage gas pressure regulators


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## trout (Mar 21, 2012)

jbyoung00008 said:


> Is this something that happens all the time or only when you have nice fish?? LOL


probably!

happen to have a perfect example as of my setup today. i normally run 30psi. high psi has been dropping from 800 just over a week now...no ill effects until the topic is brought up....irony i suppose?










also, i would guess things depend on how effective your diffusion is......in terms of a drastic change anyways


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## 2wheelsx2 (Apr 21, 2010)

trout said:


> probably!
> 
> happen to have a perfect example as of my setup today. i normally run 30psi. high psi has been dropping from 800 just over a week now...no ill effects until the topic is brought up....irony i suppose?
> also, i would guess things depend on how effective your diffusion is......in terms of a drastic change anyways


Holy smokes! That was fast! Didn't you just fill that tank earlier this summer? What size tank is it and how long did it last?


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