A few co2 injection questions.....

[TrashmanTodd]

I have injected C02 on my tank. I have read that some people set it up so the co2 turns off with the lights, while others like me just keep the CO2 going. I do it because i'm affraid if I let the CO2 turn off when the lights go out will have to much of a shift in my PH. Right now the way have it set up it will go from around 6.7-6.8 when the lights ore off to 7.0 when the lights are on. Will I be safe to do it the other way and if so what kind of PH shifts are safe.

The second question, is that I'm about to set up a smaller tank and instead of setting up another CO2 system I would like to split the line right after the cylinoid(sp). Will that work? I'm assuming I would have to have a valve and bubble counter on each line, right?

Thanks for all the great help gang! :cool:

Trashman

[Mgamer20o0]

i used to have it going on and off. now i switched to on all the time because i was to lazy to set the timer back up. i never saw any effects with the fish i have.

i have seen multiple output needle valves. that way you can adjust the amount in each tank.

http://rexgrigg.com/miniman.JPG
http://rexgrigg.com/sale

[fresh_newby]

I have injected C02 on my tank. I have read that some people set it up so the co2 turns off with the lights, while others like me just keep the CO2 going. I do it because i'm affraid if I let the CO2 turn off when the lights go out will have to much of a shift in my PH. Right now the way have it set up it will go from around 6.7-6.8 when the lights ore off to 7.0 when the lights are on. Will I be safe to do it the other way and if so what kind of PH shifts are safe.

The second question, is that I'm about to set up a smaller tank and instead of setting up another CO2 system I would like to split the line right after the cylinoid(sp). Will that work? I'm assuming I would have to have a valve and bubble counter on each line, right?

Thanks for all the great help gang! :cool:

Trashman
Yo trashman...that pH shift is negligible. The fish will be fine. I have mine go off at night, if not for anything else, there is no need to waste the gas when the lights are off. No lights...no carbon utilization...the pH shift is not an issue.

As for your second question, ou just need a splitter...check this out

http://cgi.ebay.com/2-way-Brass-Co2-splitter-for-solenoid-gauge-regulator_W0QQitemZ250018659638QQihZ015QQcategoryZ 66794QQtcZphotoQQcmdZViewItem

[WeeNe858]

spend a little money and get a ph meter its turns your system into a fully automated one :]

http://www.milwaukeetesters.com/

[TrashmanTodd]

Does the CO2 turning off with the lights mess up the cylinoid?

Trashman

[Native American]

Only if you have the regulator cranked way high (i.e., showing a lot of psi on the low-side gauge) along with the needle valve cranked down tight to control the bubble count...IIRC, the solenoid will work too hard to unseat its internal sealing surface and will burn out in short order.

If you're using the minimum pressure necessary to get the proper flow of bubbles, w/ little or no needle valve adjustment to maintain it, you're solenoid will last a long time.

BTW, some natural waters undergo a pretty hefty pH change whenever it rains...this is a spawning trigger for many species of fish.

v/r, N-A

[Rex Grigg]

A good solenoid will have a working pressure around 100 psi. Since we normally only run our aquarium systems in the range of 20 psi you can't damage the solenoid.

Also a good solenoid is rated to millions of cycles. This doesn't mean that any one particular solenoid will not fail quickly. It means that if you take a group of them, say 10, and start testing them that you will obtain an average life span in the millions of cycles.

[Native American]

A good solenoid will have a working pressure around 100 psi. Since we normally only run our aquarium systems in the range of 20 psi you can't damage the solenoid.That's the key..."good" is associated with "purpose". I'd swear that the solenoids I got w/ my Milwaukee setup are just like the low-pressure--higher-flow types (usually run at 20cfh) used for shielding gas on small welding setups. Off the tank, they sound like them too (loud w/ a very evident "kick"). These have a relatively large sealing surface and cannot handle high pressures.

Rex, you discount the people who crank on the regulator then wind down the needle valve. They get the right bubble count, but if they have this type of solenoid, it cannot last.

Mine did not have labelling on it (just a generic Milwaukee regulator w/ bubble counter and solenoid for $68 new-in-box). I keep mine at the lowest pressure possible, so I expect that million-cycle service life. The Milwaukee is a decent dynamic regulator, but under static conditions (solenoid closed, zero gas flow), the pressure rises a bit. It's all easy to control if one follows the directions in the box, but if one does it the other way (regulator cranked in, needle valve tightened up a bit), you get that larger pressure rise w/ the solenoid closed.

My next CO2 setups will be better units w/ better parts that I assemble myself, w/ a finer-thread needle valve, and a different solenoid (higher pressure-low-flow construction, like a Clippard). Still, properly adjusted, my Milwaukee MA957's are just fine.

v/r, N-A

[micynyorkies]

It's all easy to control if one follows the directions in the box, but if one does it the other way (regulator cranked in, needle valve tightened up a bit), you get that larger pressure rise w/ the solenoid closed.
v/r, N-A

What is the appropriate way to do this? I got mine used, with no box. I want to do it right!

Also, what is the approximate psi my system should run at? I've been reading that it should be 1 to 20 psi.

[Rex Grigg]

Depends on the regulator. I have built systems that work fine at 7 psi and others that have to be at 20 to work. There are a lot of variables.

And the correct way with a decent regulator is to open the cylinder valve all the way, set the working pressure at 10-15 psi and then adjust the needle valve.

Be warned there is one brand of regulator that can be damaged or destroyed if you don't follow their exact detailed instructions on opening everything up. That to me indicates a poorly designed product.

[micynyorkies]

Thanks! I also got some exact instructions from Milwuakee Instruments. They were very explicit. I'd like to post them, but they are long.

[Rex Grigg]

I know. I have seen them. And I MIGHT have been talking about them.

[mcr2582]

CO2 will lower the pH in your tank. This is how a controller works. You set a pH level and when it goes above that, it turns on the CO2, and when it drops below it turns it off. Of course you have to set it below your aquarium's natural point. You can adjust the buffering capacity of the water and add a little baking soda to push it to turn on the CO2.

Without a controller, people often turn off the CO2 at night because without light, the plants don't photosynthesize. However my tank with the controller will turn it on even with the lights off since it's going by pH. In theory leaving it on all night could negatively affect your pH, causing it to drop since it isn't being consumed. But at the low level you must be using to run it all the time, it probably wouldn't be a problem either way. The main thing is to monitor your reactor... if you see a large bubble forming, you should turn it down.

I run my main regulator at about 20psi and use a needle valve to lower it to 1-2 bubbles per second. As the pressure in the tank decreases, I have to open the main valve more to get it back to 20psi or so. I do have a splitter and second needle valve going to a second tank. I split it before the solenoid so it runs all the time at a slower rate. I use Tom Barr's homemade reactor design in that tank and it works quite well. The 150 gallon tank with the controller has a big reactor with bio-balls in it. I'm not sure what I will use in my new tanks.

Michael

[Rex Grigg]

The cylinder valve should be fully open or fully closed at all times. The CGA 320 valve is not designed to operate in any other positions.

You then adjust the working pressure of the regulator using the adjustment built into the regulator. Note that some regulators have a fixed working pressure which I find rather short sighted.

[wesknox]

I have an Octopus controller and got tired pretty quick of hearing the X-10 module clacking every time it cycled (very frequently during day). I teed off another valve on the low side and adjusted this to be very close to the nominal amount of CO2 needed during light periods. This drastically reduces the number of solenoid cycles...which my wife is also happy about.

One trick I used to give better control over bleed valve adjustment is to put a two to three foot section of teflon capillary tube (approx .5mm bore) in CO2 line after the solenoid. The resistance of this piece of tubing makes the valve setting much less sensitive to adjustment. I had this tubing from the hospital I worked at...was part of gas sampling mass spectrometer from Perkin Elmer. I inserted this inside a length of silicone airline and the OD of the capillary tubing was a firm press fit to the ID of the valve. You might also seal with silicone of these dimensions don't exactly work for your valve. A 60cm length is available for $5 on Perkin Elmer's web site; http://las.perkinelmer.com/Catalog/ProductInfoPage.htm?ProductID=WE024375


Wes

[Native American]

I know. I have seen them. And I MIGHT have been talking about them.They're written that way because it's not a great regulator for the job (low flow for aquariums). When I get my MIG welding setup, I'll probably put one of my Milwaukee regulators on the shielding gas bottle and install a better one for the aquarium.

If you want stuff that works for an aquarium...well, I'll put in a plug for good stuff that is thoughtfully designed, purpose-built for the job, and will work:

Quality CO2 Gear, not Milwaukee (http://www.rexgrigg.com/sale.html)

v/r, N-A