Assurance Needed

VaughnH

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Jan 24, 2005
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A check valve that takes 12 psi to open is the wrong one for this use. You should be able to easily suck the check valve open, but possibly not be able to blow it open. The piece of equipment the check valve needs to protect from water is the regulator, so it has to be after the regulator. If the check valve is right at the regulator water can creep back to near the check valve overnight, then you can't get CO2 flow back until all of that water is pushed back out. So, in my opinion the check valve needs to be close to where the water would come from, which is my external reactor for my setup. I don't use a bubble counter, but it makes sense to assume that bubble counter water is the most likely to get back to the regulator, and put your check valve right next to the inlet to the bubble counter. So, where you put it depends on how your CO2 system is plumbed.

If you put that 12 psi opening pressure check valve on the inlet line to the bubble counter - between it and the needle valve - it should work fine. You will just have to keep the regulator always set above 12 psi. At any other location I would worry about the 12 psi possibly damaging something.
 

MediaOne

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Sep 15, 2006
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Vaughn: I am not new to this type of system. I own 3 of them and have run them on calcium reactors (marine aquariums) for approx 15 years now ;)

The only thing I am not experienced with here is this new check valve and a connection with a "pressurized inline reactor".

Your comments are appreciated.

I have my regulator set at 15PSI now (and I have in the past) and it is working well. Indeed the check valve is between the needle valve and the bubble counter.

The fact that water can "creep" back toward the check valve is interesting to me, as I doubt my Eheim Pro 3e is producing over 12 PSI. That being said, it MUST be the cause.

What you are essentially saying is by moving the check valve closer to the reactor the check valves stops water flow also? Is this how it will play out if I move mine?

I can definitely see your point about not wanting all that water in the line. Especially at lower gas flow rates.

Thank you,
 

VaughnH

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My hypothesus is that water creeping back in the CO2 line is caused by the CO2 in that line being absorbed by the water. I didn't come up with this idea, I got it from someone on one of these forums. As long as the CO2 is turned on, CO2 enters the line faster than it dissolves into the water, but with the CO2 turned off, the water can move towards the CO2 source. So, when I used an in-tank difuser, I kept the check valve up near the top of the tank, and water stopped ata the check valve. Now that I use an external reactor under the tank, I keep the check valve near the reactor to minimize the amount of water that can build up in that line. It appears that the water can't go past the check valve, and logic tells me that would be the case. But, CO2 also isn't going back thru the check valve, it is instead dissolving into the water and thus disappearing. I think this is what is going on.

At one time I kept the check valve near the regulator, when I had an in-tank difuser, and the line was always near full of water down to the check valve in the morning before the CO2 solenoid opened. But, I don't think any water has ever gotten into my regulator.
 

MediaOne

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Sep 15, 2006
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VaughnH,

Thank you for taking the time to give me your thoughts. When I get a little more spare time I will try to place it closer to the reactor and see how that plays out. For now, I will run the CO2 full time to ensure my equipment is protected, and so that CO2 availability remains relatively constant.

Regards,

MediaOne
 

Carissa

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Jun 8, 2007
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Just a thought that crossed my mind as I was reading this over. Tom mentioned that algae will take advantage of the lull in growth when the plants are in the adaptive phase when co2 levels change. I've had a lot of issues lately related to this, not so much co2 change but lighting levels changing since I upgraded my lighting. And I also know (the hard way) that it can take weeks for plants to adapt to a change in co2 or increased lighting. Probably true for some other variability in conditions too (ferts etc.). So in order to really know if a change is actually "working" to solve the problem you have to wait a good 6 weeks if you want to be absolutely sure. Initially a change may cause immediate bad effects (algae etc.) but that doesn't mean it's not working in the long term, it just means that the plants are in the adaptive phase. Maybe if the 6 weeks goes by and the algae is manually removed as much as possible, the plants will suddenly bounce back. Anyway I guess the gist of my comment here is that initial results can be misleading, it can be hard to diagnose and accurately resolve complex problems unless you only make one change every 6 weeks which takes a lot more patience than most of us have. Well me, anyway. When I make changes I'm usually at the tank the next day peering around for good or bad signs.