DIY Inline reactor vs. Ceramic diffuser


Guru Class Expert
Jan 22, 2008
Vista, Ca
Im sure this has been asked before but i was not able to get a good answer searching around. A well respected member over at theplantedtank recommended i switch from my diy inline reactor to a glass ceramic disk diffuser as i would get better results with less gas use. What is your take on it? Is it better to mist the tank with tiny co2 bubbles or completely dissolve them in the reactor? I would think that dissolving them completely would be better then tiny bubbles but don’t understand the science portion to make a definitive decision.

Tom Barr

Staff member
Jan 23, 2005
This is the CO2 "mist" vs the dissolved form of CO2 gas.

You can add the CO2 in a more active manner, blasting it through a venturi or intake of the powerhead etc.

Many do not like the bubbles(so they say, ADA does not seem to mind):rolleyes:
I wonder why venturi, needle wheel and other methods get such harsh criticism for that and ADA is not?

Go figure.

Many simply do not like more things in the tank.
Nice looking glassware is a trade off by making it look nice and obvious so that folks keep an eye on CO2, which is not bad, but now you have it in the tank and lots of bubbles flailing all over.

I have a few bubbles with the venturi, not much really and then have a disc as well in a 60.

I've had disc off and on over 15 years or so.
You can try it.

I'm not sure it helps or not really, vs any other form of CO2, as long as each one is used right and you get enough CO2 delivered to the plants.

The gas bubbles appear to clean plants and break up boundary layers pretty good, I've suggested the gas phase allows transfer of dissolved gases faster into submersed aquatic plant leaves.

Tom Barr


Mar 7, 2008
I just switched from a Grigg style inline reactor to an inline ceramic diffuser, mainly because I wanted improve to circulation and do away with the head loss from the reactor, but in terms of one method being more efficient I don't see a huge difference. My bubble count is about the same.