Are you refering to those $6 soil ph probes? If so, they are notoriously inaccurate.

You can't make a sow's ear from a silk purse. (or whatever the saying is...) Get the best potting soil you can afford for your growroom. Most commercial brands are ready for use, trouble-free, and buffered to maintain healthy growth. Cheap mixes are hit-n-miss for both content and quality. Most need ammending, which makes them more expensive than the commercial mixes.
Rusty Trichome Reviewed by Rusty Trichome on . first grow Here is what I got!!! 3 white widow seeds planted on Aug 12. Controled temp at 75-80 degrees. 400 watt HPS light on 16/8 with a timer. sounds all great and fine except, the plants are almost a month old are only about 2 inches tall??? Is this normal, when will they start to grow? I have repotted them into a 3 gal pot after about two weeks in a solo cup. The roots were long and reaching the sides of the cup. I water when the top of the soil is crusty and dry. Any help would be greatly Rating: 5