07-25-2020, 07:58 PM
Join Date: Apr 2005
Location: Brentwood, CA, USA
iTrader Positive Rating: 100%
| | Re: CO2 dropper checker questions
Originally Posted by mistergreen
If you're not adding any CO2, your CO2 level in your tank should be around 1-2ppm.
As I recall, Ms Walstad measured CO2 in an El Natural tank and found that it had something in the range of about 20 ppm before the lights came on. Once the lights were on, and the plants were growing, the CO2 level dropped way down. That is the reasoning behind her recommendation that we use a rest period in the middle of the day - it allows the CO2 level to rise again to a useful level. Also, years ago it was shown that atmospheric CO2 raises the tank CO2 to about 3 ppm. Someone more skilled than me calculated the theoretical ppm of CO2 from the atmosphere and arrived at the 3 ppm number, too. Since then we have had numerous debates about this, so I'm not at all sure what the "right" answer is.