Re: Bubbles During Water Changes

mark.fisher at tpwd_state.tx.us 

>My plants pearled for 2-3 days after a water change, and I suspected 
>they were CO2-limited (this is back when I did not fertilize with 
>I bought a LaMotte CO2 test kit, and measured CO2 after a water 
>change (3-4 ppm) and when the plants stopped bubbling in 2-3 days (0 
>ppm).  This prompted me to add CO2 via the sugar-yeast method, and my 
>plants bubbled all week long.  CO2 was now 10-15 ppm.  I later 
 >graduated to a 20# cylinder, and finally to PMDD.

You would need more than 3-4 ppm of CO2 to keep your plants bubbling for 2-3
days.  3-4 ppm is very low.  I got a 7ppm reading before I started adding CO2
and my plants didn't do any bubbling of the kind.  Only after a water change
did they do that. 
>Others have experienced pearling after a water change, and they 
>already add CO2; obviously, CO2 is not always the culprit, but it was 
>in my case.

I don't think your case was what you thought it was.  In my opinion you are