I checked my PH at 6.4 and reserved some of the water for degassing and then checked it again at 8.0.
If I have a PH difference of 1.6 after degassing, would I have 48 ppm C02?

What I done was:
If 1 x 30 = 30ppm (1 being a total of say ph 6.4 to ph 7.4 would = 30 ppm)
Then would 1.6 x 30 = 48ppm (1.6 is the difference, say ph 6.4 to ph 8.0 )
Is this correct?

No, it isn't correct. To start with, this method is not accurate for determining how much CO2 is in the water. The assumptions behind the method are rarely correct. Then, even if a 1.0 pH change did equal 30 ppm, a 1.6 change would represent 3 X 10 to the 1.6 power, or 120 ppm, not 48 ppm. If you actually had that much CO2 dissolved in the water your fish would all be dead.

Buy or make a drop checker and use it per the threads on this forum to measure how much CO2 you really have.

Hi Hoppy,

I thought I read somewhere from one of your older posts about pouring the water back and fourth from glass to glass to degas it faster. From the best of my memory (which isn't good anyway) that the PH difference of 1.0 would be around 30 ppm C02. So this morning I did a PH reading of 6.4 and then poured the water back and fourth for 10 minutes at a hard pour. Then did another PH readiing and got a 8.0.

Not long ago it was suggested that I pump up my C02 just a little which is what I did and the next day, all of my Platies were at the surface. So I degassed it and turned it back down just a little. Now everyone is happy and I'm starting to see just a little bit of purling.

My wife won't let me spend any money because were trying to save up to move to KY so getting a Drop Checker will have to wait a couple weeks. Also, I am almost out of my testing supplies until then. So I'm trying to find another way that isn't to hard but still give me a fairly accurate level of C02.

Any suggestions.

I think I might just forget about trying to figure out how much C02 I have until I can afford to get a drop checker. After all, the drop checker has only been around and discused for such a short time, what is it, maybe 6 months or a year? Everybodys plants grew pretty good without one. I guess I'll just bump it up and watch the fish. They are our best indicator anyway. I was just hopping that I could avoid stressing them during my adjustments.

Hmmmm.... I wonder what the next best tool was before the drop checker?

A little sarcasm... maybe. I've been trying to read and read and figure all this out for over a week now and I still haven't got anywhere.

Thanks for all of your advise.

Joe

People who have the experience can tell if they have enough CO2 by watching the plants and fish, but I found I lacked adequate experience. That is the "tool" used most successfully before we all got started trying to actually measure the CO2 in the water.