I've got a standard Rex Griggs reactor (2 in. diameter, 24 in. long) in line with my Eheim 2217. 72 gallon tank, and I just put a drop checker in today, but the color is not changing one little bit, no matter how high I boost the BPS. Also, it takes a significant amount of time for the gas to dissolve in the reactor. Quite a bubble develops in the top. There are no leaks I promise. I've checked about 6 times on every connection. It feels like there is air in my canister and not CO2!!! The pressure gauge still hasn't dropped below 1000 PSI in my paintball tank. Could it be filled with air? The tanks were freezing cold after being filled, so I figured they were filled with CO2. Could air have gotten mixed in? The drop checker is close to the output of the filter. Simply put, the system acts like I'm injecting air and not CO2. I'm just confused honestly. Any ideas?