I use a Master Test Kit, by Aquarium Pharmaceuticals, Inc. Sold at Pet
Smart. I suppose different companies make different kits. More
important for a pH kit to be fresh, they don't last but a few months
and if yours is left from last year you probably need a new one.
There is a high and low range pH kit in the Master Test Kit and the
high range is graduated in .2 increments from 7.8 to 8.4 with a low of
7.4 and high of 8.8. Your morning and night readings should be within
.4 of each other if the pH is stable in your pond.
One German Degree = 17.9 ppm
6 German Degree = 17.9 x 6 = 107.4
The test liquid measures in dh and there is a chart in the kit so you
don't have to do the multiplying, but it is the same thing and now you
can get your calculator and make your numbers like theirs, if you
>The test kit I have (Tetra Pond) uses dh (German degrees) instead of ppm.
>It seems the vast majority of posters use the ppm standard, so my water
>results always look out of kilter compared to those postings.
>Also, many people seem to have highly accurate PH readings, like 8.3 . . .
>these kits are color coded, and you take .5 jumps. My water is staying
>between 8 and 8.5, but I just read that the scale is like the Richtor
>scale - each point is 10 times worse than the previous point. So I can
>understand that accuracy would be paramount. What test kit gives such a
>TIA - Lee