Water circulation, 295 GPH filtration, co2 diffuser 3in1
This is how efficiently you can use a power head as a co2 diffuser. Co2 goes thru tubing and water pressure breaks it into small bubbles which easily dissolve in the water. It isn’t the most efficient way of distributing co2 in your aquarium, but on my 40 gallons breeder with 3 bubbles per sec I had ph 6.8/6.6 and gh/kh 5/6 co2 close to 30ppm.
Those double sponges (3 of them) I ordered from China for like 3-4 usd for all of them. If you are willing to wait 2-6 weeks it is always better to buy the same stuff cheaper from china thru e-bay.
While using this method you might experience bba algae in the spots where the powerhead shots co2 directly. It is caused by spot co2 fluctuations. It is much better to use glass diffuser and then use a power head to spread those co2 bubbles around your aquarium evenly.
This is a Ph/Kh chart to read how much co2 you have in the water. You measure kh and then ph and read where it crosses. It will tell you approximate amount of co2 in your aquarium. Check min 1 hour after co2 is on.