DIY C02 this cant be right!!!!
I set up a 2 2 litre bottle C02 rig on a 72 gallon tank on thursday afternoon about 1 or 1:30 pm. I used a mix I got off the net somewhere (1 cup sugar, 6 cups warm water, 1 tsp yeast, and a tsp baking soda) hooked it all up to the pick up of a Fluval 304 and not ten minutes after it was all hooked up I started seeing bubbles, so I tested the PH & KH at about 2:30pm and got these results PH 7.2 KH 7 and going by the chart I have that's about 13.3 ppm of C02, 6:30am friday PH 6.8 & KH 7 thats about 33.3 ppm, 6:30pm friday PH6.8 KH 10 thats up over 40 ppm. Fish seem to be doing fine still eating well. And I might add I am using a spraybar near the top of the tank so I have a far bit of surface movement so I should be losing a far bit, and from what I read 2 2 litre bottles won't hardly keep up with a 55 gallon tank, these readings can't be right, can they?