I set up a DIY co2 system a while back and it seemed to be working well with bubbles coming out of my glass diffuser. Then I realized that the bubbles were reaching the surface and being wasted. I tested it and the results support my observation: the co2 is around 4-5 ppm. I've already tried doing a bleach soak (2 scoops of bleach to 10 scoops of water) but it didnt help much. What should I do to get the bubbles to dissolve?? Any advice would be welcome.