CO2 Solenoid Not Stopping Flow

[ppurcell]

I guess I'll try this in the local forum too...

I just installed my first calcium reactor (DIY) on my tank yesterday and I am noticing that with the Pinpoint pH controller, that even after the controller shuts off the solenoid that it continues to bubble for a long time. I am wondering if perhaps the solenoid isn't sealing (I bought it used). How long do they usually continue to bubble after shutting off? I am bubbling at about 30BPM.

How long do most people see bubbles coming through the bubble counter after the solenoid shuts off?

 

[adamjr]

Do you have a check valve between the solenoid and the bubble counter? If not the bubbles you are seeing may be the CO2 in the line being displaced by water which is something you want to keep away from your solenoid.

Or it is the solenoid not sealing.

If the bubbles do stop then I would beleive it was what I wrote dirst and you need a check valve.

If you need to install a check valve then you should also remove and clean the solenoid to prevent corrosion from the saltwater that has already contacted it.

Adam

 

[ppurcell]

I have three check valves (the cheap ones) between the water and the solenoid, but I am not sure that it hasn't ever seen water.

What is the procedure to clean the solenoid? Run vinegar through it?

 

[adamjr]

To clean it you want to run fresh water through it and allow it to air dry.

What you really want to do is not so much to clean it but to flush it of any salt which will corrode it.

As far as what type of check valve you don't want to skimp on quality. You can get some lab grade john guest type check valves from McMaster Carr. www.mcmaster.com

Adam

 

[ppurcell]

do you have a part number by chance?

 

[adamjr]

Try part number 51055K171. It is on Page 153 of the online catalog about half way down. Food grade quick connect, which we know as John Guest, are page 151 to 153.

I would have put in a direct link for you but their catalog is java script based so I can't.

Adam

 

[Sullyman]

You'll probably need a new co2 solonoid too, mine was never right again after a check valve failed and it got wet. I'm going to use your info too, thanks Adam.

 

[ppurcell]

Thanks, I just ordered one. It says it is for air only. Any idea how long it should last before the CO2 breaks it down?

 

[softbal4]

do you know where i can get a new solonoid? mine is leaking and I go thru co2 really fast...5 lb bottle every 6-8 weeks. thanks

 

[ppurcell]

I was just researching that myself. Are you certain that your solenoid is leaking? Have you applied soapy water all around each joint from the bottle to the reactor to make certain that none of your connections are leaking?

It seems to me that if you are leak free and not over-feeding your reactor then you shouldn't go through CO2 very much more rapidly than if you have a properly working solenoid. I think the main benefit of a solenoid is that if your bubble rate is too high, then the controller (or your timer for day/night operation) can shut it off when the pH rises beyond the high-level set point.

At any rate, Marine Depot sells one for $49. I looked around and didn't see any that were cheaper. If anyone has a less expensive source, please share...

http://www.marinedepot.com/md_viewItem.asp?idproduct=CO3171

 

[softbal4]

it is indeed the solonoid. I took the regulator in when I fill the tank and it has a leak at the connection of the solonoid. the solonoid (I don't believe is working) I bought this used and I can have the regulator either plug in or un plug with no change ( co2 runs with both). all help is appreciated...sorry for tagging along on your thread.

 

[ppurcell]

I just ordered and received the check valve. $15 shipped. Not bad.

After a couple more days messing around with the CO2 feed, it appears that my solenoid isn't even coming close to sealing when it is shut off. I suppose I need to order a new one.

Also, I think I'm getting CO2 into the atmosphere around the tank. My sinuses sting a bit after being in the basement with the tank for any length of time. I installed a 4" fan which is vented outdoors, but it doesn't seem to have completely solved the problem. Can anyone share any ideas? I've tested every connection from the CO2 cylindar to the reactor and none leak. So, it must be coming out with the effluent which is slow dripping into the first chamber of my sump which has lots of air bubbles from the overflow.

 

[adamjr]

ppurcell

Your effluent shouldn't be off-gassing CO2. The CO2 should be well mixed with the water in order to create carbonic acid.

One thing I have heard of people doing to increase the pH of the effluent is to have the effluent drip into a vessel that is aerated. Then have that overflow into the sump.

It seems you may still have a leak somewhere. Do not underestimate the danger of CO2 being vented into the air you breathe.

Mix up a thick batch of soap water. You only want to thin the soap slightly. You want it to be able to flow into connections but be thick enough to trap bubbles.

BREATHING CO2 CAN KILL YOU. The old adage "you can never be too careful" applies here in spades.

Good luck.

Adam

 

[adamjr]

I just re-read your initial post and saw your reactor is DIY.

Is this the design of the CA reactor you are using? If so I have some ideas as to why you possibly have raw CO2 off-gassing.

If the blue line at the bottom after the gate valve is your effluent output then I see a problem. CO2 comes into the pump and exits through the effluent line. The CO2 isn't getting sufficient dwell time and isn't mixing with the water.

Your diagram differs slightly from your proof of concept model (diy unit) so I am just guessing. I think I see a lot more valves then you need. The line coming off of the square plug that goes into a tee is where your effluent should be coming from.

Here is a way I would simplify your design.

1.) Remove the gate valve coming off the cross at the right above the PVC ball valve.

2.) Use the line coming off of the square plug at the top for your effluent and attach it to the gate valve removed in step 1.

3.) Remove the rest of that 1/4" polyethylene with the three remaining John Guest ball valves.

4.) Plumb your tank water (input water to the reactor) and the CO2 into the tee that is just above the pump.

5.) Plug the line coming out at the top left.

You can put a valve between the input water and it's source to shut off water for refilling and cleaning and maintaining the unit. That valve should be wide open in use or closed for servicing. The input volume is controlled by the effluent volume.

Follow the K.I.S.S. rule. The second S is not meant as an insult it is just how the acronym was presented to me at a very young age.[

 

[ppurcell]

Adam,

Thanks for the suggestions. I just tested all of the connections for leaks using soapy water for the 3rd time. Still no leaks.

As far as the design modifications, some of your interpretations don't match with the design. Let me explain and see where that takes us.

1. The gate (ball) valve on the cross is to drain the reactor. It is normally closed.

2-3,5. The top line off of the square plug is what I use to purge the system of air during startup. I close the valve below the T on the right side and open the other two. After all air is purged, then I close the horizontal valve and open both vertical valves. This way any accumulated gas bubbles get recirculated and the effluent comes out the elbow on the 1/2 PVC. Here is the thread I created when I was troubleshooting the excess bubble problem: http://www.reefcentral.com/forums/showthread.php?s=&threadid=953736

4. Input water comes in from the bottom on the 3/8" blue line you see in the picture. The black thing is a check valve, and the white/black valve is a needle to control flow through the reactor.

Originally, there wasn't a recirculation mod and I only had one effluent output coming off of the 1/2 inch T on the loop elbow. I added the 1/4 inch tubing and the additional output on the square plug first as a means to eject excess trapped air. But second to recirculate any accumulated CO2 to try and ensure efficient use.

for the past two days, I've been running the reactor with the gas recirc modifiction disabled and with both effluent outputs open. The effluent is dripped into the first chamber of my sump which is highly aerated due to the water turbulence created during drop into the chamber from the tank.

Current CO2 bubble rate is 20 BPM and the effluent drip rate is about 40 drips per minute. Not sure what that amounts to in terms of ml/min (15-20 maybe) but it is a steady drip.

As an FYI, the effluent now flows through two cannisters filters which are setup as a second chamber filled with ARM. You can see them in the beige cannisters behind the reactor.

 

[adamjr]

Do you have a picture of the current setup?

What is the pH of your effluent? If you are using ARM then you want it to be around 6.0

Adam

 

[ppurcell]

I've been maintaining the effluent around a pH of 6.5. When I measured this morning I Alkalinity was 2.96 meq/l (8.29 dKH) and Calcium was 420.

The effluent is being measured in the pH probe sump which sits between the reactor and the 2nd chamber setup. You can see it in the picture, it is wire tied to the 1/2 inch PVC right by the top union.