I get the sense that there are 2 main camps re: co2 monitoring:
1. use a drop checker and try to manage a good lime green color
2. measure ph and shoot for a go for a 1 ph drop
The problem with #1 is that co2 (carbonic acid in the aquarium) isn't the only thing affecting ph in the tank, so the co2/kh/ph relationship that the drop checker is based on is inherently inaccurate. What degree of inaccuracy actually exists is dependent on the individual tank, so could be right on the nose and some could be wildly off target.
Using a ph monitor/controller/meter is a better option b/c with it you've eliminated the kh aspect of the relationship (I think). Because you are accurately measuring only one thing now (ph), you can target a specific co2 level independent of any knowledge of the kh in the tank. if you aim for a 1 ph drop you'll be roughly in the neighborhood of 30 ppm co2. At least that's my understanding of the issue, more knowledgeable people can chime in and correct me if I'm off-target.
There was only one catch and that was Catch-22.
Last edited by aubie98; 10-20-2018 at 05:47 PM.
Reason: premature posting