| | Re: CO2 Diffuser
I am pretty sure I have found the problem - it was a leak from the top of my bubble counter attached to my CO2 valves, guages, solenoid and cylinder. It was initially leaking when I first installed it (hence why I did a complete soapy water test weeks ago where I tested all the fittings for leaks - there were none). Moving the tank around must have broken the seal at the top of the bubble counter - its a dodgy bubble counter.
I have learnt a simple trick to test a CO2 supply tubing once you are satisfied all your gas cyclinder fittings aren't leaking. You simply put the end of your supply line under water in the aquarium (no diffuser attached) and watch the bubble count. It should be identical to the bubble counter - I noticed yesterday that it was much lower coming out of the tube. Today I took apart the bubble counter 'again' (its been a few times :j), noticed that the top of the counter has no o-ring. Its just plastic on metal. That doesn't look right, will have to fit my own o-ring soon. Put vaseline again on the thread and the top of the plastic bubble counter cylinder where it meets the metal (where I intend to put an oring soon).
And the diffuser is working better than it ever has. At 1 bubble per 3-5 seconds I have a cascade of miniature bubbles now. I suspect I am going to see less backflow now even without a check valve fitted in the line. Seems not having a check valve is a good indication of the health of your CO2 supply. Heaps of back flow means you have a leak. The check valve inbuilt in the bubble counter is the most important one but I will fit a check valve in the line asap as well.
I noticed today that the back flow problem really only became a major issue this last week. The diffuser worked OK for the first 2 weeks, even if it did partially fill with water.
Don't buy cheap CO2 setups people - ain't worth it - you will spend weeks sorting it out, redesigning it. It didn't look cheap, and the price was pretty high, but seems the bubble counter is doddgy as hell. Its made in Taiwan, not China, I was wrong on that point. The diffuser has good reviews on Amazon, so I don't think its the diffuser anymore.
Today, before sorting it all out, I fitted the diffuser that came with the CO2 setup (I had upgraded the diffuser and never used it before). Its a joke. The diffuser surface feels smooth as rubber, not the coarse grain you would expect. After waiting 3-4 hours for the gas to come out, I put the old one back on. The manufacturer says you need 3-5 bubbles a second and wait 2-4 hours for it to work. Sounds ridiculuous amount of gas for a 6 gallon nano tank.