I'm curious what everyone runs on average for bubbles per second. I have a 75 gallon plus a sump. There is a homemade wet dry in the sump so I'm likely losing quite a bit of co2 there. My bubbles/second are probably close to 10 (too fast to count) and I only get a ph drop off around 0.7. My plants are responding so even if I blow through my 5# tank every month or so it should work.