I have a 29 gallon aquarium running an Aquatek CO2 regulator going to a glass/ceramic diffuser. My 20oz cylinder is only lasting about 4 days from install at a bubble rate of 1.5 bubbles per sec. The high side gauge of my regulator doesn't work but when I install the cylinder and open the on/off valve it jumps to 40-60 psi on the low side. This regulator has very little product documentation so I do not know much about it. I do run pps and so the CO2 is on 24/7. How long should this last? I'm not worried about once or twice a month having to get it refilled but every 4 days is a bit to much.