The Milwaukee Ph pen digital tester is about $20 on ePay and is considered a respectable quality meter. Here's a few sticky threads on Ph:
http://boards.cannabis.com/plant-pro...hy-how-do.html
http://boards.cannabis.com/basic-gro...nutrition.html

If in doubt flush, flush, flush.

You could save the money and just do the following "Old fasioned Ph test" although in old fashioned times 40 years old was a human life expectancy to die of "old age".... Maybe that's becaue they were eating dirt? Who am I do judge, I have to taste my cat litter to see if it's dirty. See ya!

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