# Common problem with DIY FE?. Danger to fish and cylinder?



## Nick_593 (6 Oct 2013)

Hi guys.

I have had several occurrences where a huge surge of CO2 comes out of my DIY FE system (the Fire Extinguisher) when the levels of CO2 get too low in the FE.

This has resulted in CO2 overdose in the tank, and the regulator freezing and becoming covered in ice. I have never been there to see it happened, and the closest I've come to seeing it happen is when I have come into the room and the regulator is covered in ice afterwards. The CO2 pipe will also eventually blow off the bubble counter after a huge CO2 surge into the tank, and the tank will empty.

-I assume the pressure builds at the base of the out-flow pipe inside the FE when the level of CO2 gets near the bottom.
- The CO2 level indicator on the regulator doesn't show the level of CO2 accurately either. It is either at 50bar, or drops straight down to zero when the level gets so low that a CO2 surge occurs.
-I am not in the room often enough to keep and eye on the system at all times either.

I have just introduced three new Ram Cichlids into the tank after not keeping inhabitants for a several months as I have been focusing on growing the plants. I don't want a CO2 surge from the canister to kill everything now when the CO2 level gets low in the FE.


My questions are;

1) Is this a common problem for other people with this type of CO2 injection (DIY FE)?

2) If so, could someone offer a suggestion/ solution to stopping these CO2 surges overdosing the tank with CO2?

Thanks a lot,

Nick


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## RossMartin (6 Oct 2013)

Dual stage regulators stop this I believe!!!


Sent from my iPhone using Tapatalk - now Free


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## sa80mark (6 Oct 2013)

This is known as end of tank dump theres 2 ways to solve this fisrt is to weight your new fe with regulator on and keep weighing it every few weeks / month once the fe weight has dropped 1.5kg buy a new one and replace it, the second option is to buy a dual stage regulator this will also pretty much 100% eliminate the problem although a dual stage regulator is not cheap its well worth the money

Mark


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## ian_m (6 Oct 2013)

Known as tank dump. Occurs in "cheaper" single stage regulators as they loose regulation when the tank pressure starts dropping. Some very cheap "regulators" don't even regulate, they just have a very fine pin hole (or diffuser plate) and let the 55bar pressure push through the holes. As the pressure drops holes expand/diffuser gets easier to pass and tank dumps out.

The pressure in a FE will stay at 50bar as the liquid in the tank evaporates keeping the pressure up. Once all the liquid has gone the pressure drops, causing the tank dump with poor regulators.

I have one from CO2Supermarket, which doesn't tank dump as I have observed it a couple of times now. Basically tanks pressure stays at 800psi (55bar). Towards the end of tank with pressure above 500bar (35bar) bubble rate stays the same, but once tank pressure drops below 200psi bubble rate drops and output starts moving down from 35psi (2.2bar), until output drops to 1bar odd and my in line atomiser stops working. Takes about a week to go from 800psi to empty, so plenty of warning.

I weight my FE every other water change, mine with regulator weighs 5.45Kg and was 5.25Kg two weeks later, so heading for 4-5months until empty.


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## tubamanandy (6 Oct 2013)

Never had the problem in many years of using various CO2 gas bottles - secret is use a good twin-stage regulator


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## Nick_593 (6 Oct 2013)

Brilliant. Thanks a lot guys.



RossMartin said:


> Dual stage regulators stop this I believe!!!
> 
> Sent from my iPhone using Tapatalk - now Free


 


sa80mark said:


> This is known as end of tank dump theres 2 ways to solve this fisrt is to weight your new fe with regulator on and keep weighing it every few weeks / month once the fe weight has dropped 1.5kg buy a new one and replace it, the second option is to buy a dual stage regulator this will also pretty much 100% eliminate the problem although a dual stage regulator is not cheap its well worth the money
> 
> Mark


 



ian_m said:


> Known as tank dump. Occurs in "cheaper" single stage regulators....


 


Could someone recommend a dual stage regulator? Preferably one as cheap as possible and suited to an FE?
(It would also be a good idea to mention this in the DIY FE thread, as I bought the regulator mentioned in there, but now supposed it would be best to get a dual stage regulator in the first place).

Thanks a lot!.

Nick


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## sa80mark (6 Oct 2013)

As far as I know there a no dual stage regs made for aquatics the only way is to buy a welding dual stage reg and the fittings required such as needle valve etc as a rough idea you would be looking somewhere between £125 -£175 for a good reg modified for aquatics


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## ian_m (6 Oct 2013)

How ever there are plenty regulators, not dual stage that work absolutely fine with no end of tank dump eg the CO2Supermarket one.

Easy way to see if it dumps is turn FE off (at handle) and observe over a while.


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## squid102 (6 Oct 2013)

There is a BOC 8500 Multi-Stage co2 regulator on ebay for £54.50 at the moment. It's second hand but is still boxed and has never been used. These are very good laboratory grade regulators.


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## tubamanandy (6 Oct 2013)

I think they are much cheaper than £125-£175 - have a look around


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## Andy Thurston (6 Oct 2013)

sa80mark said:


> As far as I know there a no dual stage regs made for aquatics the only way is to buy a welding dual stage reg and the fittings required such as needle valve etc as a rough idea you would be looking somewhere between £125 -£175 for a good reg modified for aquatics


 
I think thats pretty close on price
If you really wanted to go nuts you could spend £200+ on a needle valve and solenoid
It could be done cheaper but then its a waste of a good reg


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## GreenNeedle (7 Oct 2013)

Never had this problem with my Azoo regulator.  I think it can be hit and miss though with the standard cheap regulators just as it can be for any problem.  I've read of problems with the Azoo too but I've not (yet) encountered any.


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## Nick_593 (11 Oct 2013)

Hi guys, has anyone seen or use one of these before? Are they dual 'stage or dual 'guage'? I was under the impression that they were dual stage for a moment, but their pretty cheap. Dual Gauged CO2 Regulator Aquarium Home Brew | CO2Art.co.uk - CO2 Aquarium Specialists

Thanks



Big clown said:


> I think thats pretty close on price
> If you really wanted to go nuts you could spend £200+ on a needle valve and solenoid
> It could be done cheaper but then its a waste of a good reg


 


squid102 said:


> There is a BOC 8500 Multi-Stage co2 regulator on ebay for £54.50 at the moment. It's second hand but is still boxed and has never been used. These are very good laboratory grade regulators.


 


sa80mark said:


> As far as I know there a no dual stage regs made for aquatics the only way is to buy a welding dual stage reg and the fittings required such as needle valve etc as a rough idea you would be looking somewhere between £125 -£175 for a good reg modified for aquatics


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## ian_m (11 Oct 2013)

As stated they are dual gauge, not dual stage. However many people have used these types of regulators with absolutely no issue...nice consistent, repeatable, reliable CO2 level.


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