Someone always throw this response in every time someone mentions the word Drop Checker lol
So if you pull your drop checker out while it is a light green color and replace the drop checker solution with a new mix, it will take 2 hours to go back to the same light green color?
Yes, I am using the 4dkh. I am also using the little vial/container that comes with the Red Sea Co2 kit. I put in 1mL of 4dkh solution and 2 drops of the Red Sea indicator solution (blue drops). Turned a deep blue. Have not checked it yet this morning to see where it was at colorwise.