The Planted Tank Forum banner
1 - 5 of 5 Posts

· Registered
2 Posts
Discussion Starter · #1 ·
I am having a problem with the CO2 system in my 40 gal freshwater aquarium (36"w x 15"d x 17"h). I am out of ideas about what else to try. Help would be much appreciated (probably something only a newbie would miss). :help:

I am new to CO2--I have only used it since last fall. For a while I had an in-tank diffuser, but didn't get much result. The first week of January I installed an inline CO2 atomizer. It was marvelous for six weeks or so: I could see a very, very fine mist in the tank, the CO2 indicator solution changed appropriately over the day, and all the green guys pearled enthusiastically! On less than 1 bps.
Then I had a solenoid problem :frown2: and then a needle valve problem (half my fish died :crying:) and I then had to refill my CO2 tank. It took awhile to get all that fixed.

When I started it all up again a few weeks ago I couldn't seem to get the CO2 to show up in the tank. This is my set up:
CO2 tank with Archaea dual-gauge regulator=>
=>Amano speed controller =>
=>Amano plastic check valve =>
=>inline bubble counter =>
=>stainless steel check valve
(or plastic airline coupler, tried both: see Note just below) =>
=>CO2 atomizer in the output line of Eheim 2215 canister
(on the line out of the canister, on the way to the aquarium).

(Note: the SS check valve is pretending to be a CO2-proof coupler, so that I can have a few inches of the flexible white CO2 tubing at each end of the bubble counter--because that is the only way I can disconnect the bubble counter to re-fill it. The rest of the tubing is the stiff black Co2-resistant type)

--The first gauge of my regulator still reads full. It has not visibly gone down over the last two weeks, so I assume it's not leaking anywhere, or not much. I can't hear any hisses.
--The second gauge indicates a pressure of about 35, as before. Needle valve mostly open; control is by Amano speed controller upline.
--The inline bubble counter responds appropriately, more or fewer bubbles depending on how I tweak the speed controller below it.

When I first had trouble (no indicator change, no mist, no pearling) I took everything apart, including the atomizer. It looked pristine inside but I cleaned it out with peroxide. I cleaned the canister tubing, changed the filter media, impeller. I double-checked all connections as I put it back together. The "Y" branch of the atomizer, which includes the CO2 input line, is on the canister-side of the return water line; the single stem is on the aquarium-side. I changed the CO2 indicator solution.

Even if I increase the bubble rate to a stream of barely-distinguishable bubbles, there is no change in the aquarium--no mist, no indicator change, no pearling. I tried using my old CO2 diffuser inside the aquarium (both bypassing or not bypassing the stainless steel check valve). There were a few streams of bubbles rising but not a heck of a lot, and--again--no sign of significant CO2 in the water. So I don't think the problem is the atomizer. The CO2 reaches the bubble counter just fine, but never makes it to the tank. And it doesn't seem to be the check valve/coupler.

Does anything come to mind that I may be missing?
My plants are getting hungry and the algae are getting way too happy :frown2:

· Registered
199 Posts
If you open up the needle valve completely does it just keep going at the same rate or does the bubble count slow/stop eventually?

If it just keeps on going infinitely then you have a leak.

If the bubble count slows/stops then the line is pressurized equal to the working pressure and the atomizer is likely clogged. They have micro pores that clog if left unused for long periods.

Try soaking it in bleach for longer or try upping the working pressure to 40-50psi and see if it pushes it out. Don't go higher than 60psi, as the atomizer itself could split.

Also test without the check valves in case they have failed.

· Registered
2 Posts
Discussion Starter · #4 ·
Thanks to all who responded. I tried all suggestions without discovery. Waited a week for system to "catch up", cleaned the atomizer, removed and changed check valve, removed speed controller. I finally soaped all connections *again* to look for the leak that had to be there. All connections looked fine...until I accidentally dripped soap onto the *side* of the inline plastic bubble counter. Not the connections: the side.

Bubble, bubble, there's the trouble.
Not sure if it is a hairline crack or a defect: can't really see it...but it does bubble up a soapy coating.

So, I got a glass inline bubble counter and the system is working adequately now. Previously, I got CO2 mist at 1 bps with this atomizer, but now it takes a stream of bubbles in the counter to get the same mist. Bubbles go by way too fast to be countable, but are still discrete bubbles. So maybe there is still a leak somewhere. Small, because I see no change in the main tank gauge. But I do have CO2 now. What a difference! Thanks, PHX17

· Premium Member
3,075 Posts
I think more bubbles should be alright, because the common glass inline type bubble counters have smaller orifice, so smaller the bubble means a lot more bubbles.
a bubble double in diameter, the volume increase to 8 times of the original.

bubble rate is only a reference to a steady co2 flow rate, how fast the bubble rate for the tank is through observation, if you want to know the actual flow rate, need a high precision flow meter.
1 - 5 of 5 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.