Hi I have just installed a ceramic diffuser in my 100 litre tank and the cO2 bubbles come out in a few, 3 or 4, very thin streams, not really a mist but the bubbles are pretty "micro". The bubbles rise sedately upwards and are then sent off round the tank by the output of my in-tank filter. They don't make it to the surface too much, any that are still visible end up caught up in the plants. So that all seems fine. (Correct me if that's not good.. )

Only thing is the diffuser is making a faint squeaking noise all the time, I guess as the bubbles force their way through the pores in the disc. I can't think how but is there anyway of shutting it up? Or is it down to quality of the diffuser? Anyone else have this problem? I soaked the disc before installing it, which I did read somewhere was a good thing to do - although I wasn't convinced at the time.

Any help gratefully received!

Generlly, the room has to be pretty quiet to hear the bubble squeeks.
This is normal, you can clean the diffusers monthly etc real good in bleach, I add about a 50/50 water bleach mix and let soak for about 1 hour.
Then rinse good, soak in dechlor for about 15 min, return to the tank and add a little dechlor to the tank itself.


Regards,
Tom Barr

A chemistry question: when we soak something in 50-50 bleach solution does the bleach decompose the "dirt", thus removing it? Or does it just kill off any organic matter, making it easier to wash it off? For example, I soak my Magnum 250 micron filter in a bleach solution, overnight. What is the bleach doing to it? Likewise, if you soak a diffuser?

Bleach is a very strong oxidizer, like peroxide and K+ permangnate.
It destroys plasma membranes which are highly reduced biochemically(think saturated long chain fats) and produces a by product which is even more nasty and toxic.

Adding a highly reduce compound with a strong oxider will cause havoc at the microscale.

When you add CO2 to a powerhead or a pump, it'll sound much quietier if you use a fine mist air stone to bubble the gas into the suction side, the larger bubbles make an awful racket IME. the tiny ones hardly make any noise and it improves the efficiacy of the CO2 mixing also.


Regards,
Tom Barr

I was thinking if fed the co2 into the intake side there'd be a localised concentration/build up of the CO2 in the filter foam, which would degrade the foam's structure, being acidic.

Or possibly upset all those little bacterial friends and interrupt their valuable work on the fish poo front.

You're saying "How absurd, you foolish rookie" here, I am guessing!!

CO2 is pretty weak acid, attacks CaCO3, but will not go after foam nears as anyone can tell. Nor is particularly harmful to bacteria which often live in higher
CO2 locations.

Regards,
Tom Barr

Great thanks for the info Tom, I will reconfigure my tank and enjoy new levels of quietness and plant growth. Much obliged to you.

Regards