CO2 fail-safe?

[dapellegrini]

I seem to remember some discussion when I was setting up my pressurized CO2 about a few possibilities of catastrophic failure that could result in devastation of the aquarium. One of the tank "dumping" at the end of its charge and the other I believe had to do with the solenoid valve sticking open or closed (I use a solenoid on a pH probe, both from Milwaukee).

For the tank dump, are there any inline gadgets that I can get as a fail-safe? Something that would off gas if the pressure in the low pressure side of the setup went over some small limit? I think Rex Grigg sells a needle valve with some sort of dump guard on it, but not sure if that would work with my Milwaukee setup).

As for solenoid failure, I am not sure what can be done since this would be a more gradual change... Perhaps my new drop checker will offer some kind of fail safe for this once I get it setup...

If you are running a Automated CO2 system, what are you using (if anything) for these contingencies?

 

[7Enigma]

I will be going pressurized soon (hopefully within the month) and will be refilling the bottle when it gets to ~20-25% or so. This can be done by using the pressure level in the bottle itself to monitor the amount left or by a weigh scale. As for the solenoid, I think I'm going to take my chances. Fortunately with my PH setup if too much CO2 goes through the line to quickly it airlocks and then big bubbles are just rising to the surface. I don't think this would cause too bad of a CO2 increase. It would probably ruin the PH over time, but I'd rather that then a tank of floaters.

 

[Lonewolfblue]

You shouldn't have any problems with tank "dumping" if you have a check valve on the line at the tank. I have one at the tank, plus my splitter also had built-in check valves at each bubble counter. Check valves only allow flow in one direction.

 

[7Enigma]

You shouldn't have any problems with tank "dumping" if you have a check valve on the line at the tank. I have one at the tank, plus my splitter also had built-in check valves at each bubble counter. Check valves only allow flow in one direction.

I believe the OP means the dumping where the pressure goes low enough that it releases MORE into the tank, not that it syphons back into the tank. But I could be wrong.

 

[Zezmo]

Your needle valve will prevent "dump" effects. The bigger danger to pressurized going crazy has to do with Ph probes failing, clogging, or not being calibrated.

On my CO2 tank, it stays at 900psi until all the liquid vollume is used. Then when there is only gas, the pressure begins to drop off. For me, that indicates about 2 weeks until tank is empty.

 

[rkilling1]

I will be going pressurized soon (hopefully within the month) and will be refilling the bottle when it gets to ~20-25% or so. This can be done by using the pressure level in the bottle itself to monitor the amount left or by a weigh scale.

As stated by Zezmo, you will not be able to tell that your tank is ~20-25% by the pressure. You could weight it, but what a pain it would be to reset everything everytime you wanted to check it.

I seem to remember some discussion when I was setting up my pressurized CO2 about a few possibilities of catastrophic failure that could result in devastation of the aquarium. One of the tank "dumping" at the end of its charge and the other I believe had to do with the solenoid valve sticking open or closed (I use a solenoid on a pH probe, both from Milwaukee).

For the tank dump, are there any inline gadgets that I can get as a fail-safe? Something that would off gas if the pressure in the low pressure side of the setup went over some small limit? I think Rex Grigg sells a needle valve with some sort of dump guard on it, but not sure if that would work with my Milwaukee setup).

As for solenoid failure, I am not sure what can be done since this would be a more gradual change... Perhaps my new drop checker will offer some kind of fail safe for this once I get it setup...

If you are running a Automated CO2 system, what are you using (if anything) for these contingencies?

The valve on Rex's site is a low pressure regulator made by clippard, just like this one: http://www.clippard.com/store/display_details.asp?sku=MAR-1P-NR .

The way I circumvent a solenoid being stuck open, is by only having my reactor on when the lights are on (plus 1/2 hour before). So if my solenoid was to stick open, very little CO2 would be dissolved when the PH is off. I know that doesn't help with a fully automatic setup, but atleast that gives you some idea as to what other people do.

If you are running a powered reactor, you can setup your system the same way. It would be fully automatic when the lights are on and shut off when the lights are off. Just make sure to turn it on slightly before the lights come on to ensure the CO2 is at it's target level when the plants start to consume it.

And again, as Zezmo stated, you also have to deal with the pH probe going bad. There is nothing that I can think of that would stop or circumvent that from happening, other then making sure your BPS was set low enough that it wouldn't be that big of a problem if it was to continuously inject.

 

[7Enigma]

I will be going pressurized soon (hopefully within the month) and will be refilling the bottle when it gets to ~20-25% or so. This can be done by using the pressure level in the bottle itself to monitor the amount left or by a weigh scale.

As stated by Zezmo, you will not be able to tell that your tank is ~20-25% by the pressure. You could weight it, but what a pain it would be to reset everything everytime you wanted to check it.

I seem to remember some discussion when I was setting up my pressurized CO2 about a few possibilities of catastrophic failure that could result in devastation of the aquarium. One of the tank "dumping" at the end of its charge and the other I believe had to do with the solenoid valve sticking open or closed (I use a solenoid on a pH probe, both from Milwaukee).

For the tank dump, are there any inline gadgets that I can get as a fail-safe? Something that would off gas if the pressure in the low pressure side of the setup went over some small limit? I think Rex Grigg sells a needle valve with some sort of dump guard on it, but not sure if that would work with my Milwaukee setup).

As for solenoid failure, I am not sure what can be done since this would be a more gradual change... Perhaps my new drop checker will offer some kind of fail safe for this once I get it setup...

If you are running a Automated CO2 system, what are you using (if anything) for these contingencies?

The valve on Rex's site is a low pressure regulator made by clippard, just like this one: http://www.clippard.com/store/display_details.asp?sku=MAR-1P-NR .

The way I circumvent a solenoid being stuck open, is by only having my reactor on when the lights are on (plus 1/2 hour before). So if my solenoid was to stick open, very little CO2 would be dissolved when the PH is off. I know that doesn't help with a fully automatic setup, but atleast that gives you some idea as to what other people do.

If you are running a powered reactor, you can setup your system the same way. It would be fully automatic when the lights are on and shut off when the lights are off. Just make sure to turn it on slightly before the lights come on to ensure the CO2 is at it's target level when the plants start to consume it.

And again, as Zezmo stated, you also have to deal with the pH probe going bad. There is nothing that I can think of that would stop or circumvent that from happening, other then making sure your BPS was set low enough that it wouldn't be that big of a problem if it was to continuously inject.

Thanks for clearing that up. I guess the horror stories I've heard are from people that don't use a needle valve? The pressure gets too low for the regulator on the tank to work properly and it allows much more into the tank?

As for the PH, that's what I'm currently doing with my DIY setup and would imagine it would work the same with a pressurized setup (ie PH only on when the lights are on, otherwise big bubbles just rise to the surface).

 

[dapellegrini]

Thanks for the feedback. Glad to hear that the needle valve should work against a end-of-tank dump. As for a pH probe failure, I am thinking that a drop checker will do the trick.

For the solenoid being stuck open/closed, I think I will have to rely on the drop checker as well. I do use a reactor on the outline of one of the canisters, not on a power head (less equipment in the tank). My only off-switch on the system is the solenoid, which I am considering turning off at night. My BPS is around 2, so I wouldn't be worried about a rapid, catastrophic change in that case, either way.

 

[nwfish]

My Co2 system has both an electric plug that is activated if the PH goes to low (Too much Co2 in the tank). I plan on setting that plug up with a air pump that will kick in if the PH gets below the too low and hopefully outgassing my aquarium. I also plan on running only when the lights are on.

 

[Lonewolfblue]

Tank Dump:
When the main guage starts to decrease, watch your secondary guage. If it starts going up, then you will get excess CO2, as the pressure will be higher. I just noticed it when I ran out of CO2 this last week, when I upgraded my tanks on Monday. As the main guage was decreasing, the secondary was increasing. Then when I looked at the bubble counters, I couldn't tell how fast it was going. Looked at the secondary guage and it was at 50psi. Turned the secondary pressure back down by closing the valve back to 12psi, and my bubbles were back to normal rate. But the secondary, as the primary was decreasing, was increasing. So I had to keep adjusting it til I disconnected everything and traded the 10lb in for a 20lb.