I'm in the process of getting a ph pen that&#...

Blue Lab brand is the best purchase I made in PH pens. I check my DWC daily and this pen is waterproof so it doesn’t matter if you drop it into your solution, won’t hurt it. Doesn’t need calibration either.

strips really arent where it is at for precision cultivating, and it doesnt take long or much to seal that conclusion up i might test a system 20 or more times while adjusting the solution... for every system... meaning that a good ph pen with a replaceable sensor probe and a calibration kit and a good interpolating algorithm is critical. like having multiple, in case one fails. before you end up overnighting it to your rooms.... those cheapo pens really arent that bad, I have even rebuilt one in a pinch that was water damaged. take the batteries out, take the chip board out, press the on button for a minute, dry it well, use like coca cola or something and swish it around on the board, then some RO water, dry it extremely well... you might have to smack it around some or use a tool like an air compressor. Once dry, take it to a bottle of water with a known pH and see if that mark is still on point. Try another set point if you can, but it should read okay for emergencies until your new one comes in.

Unless you are taking daily readings, usually more cost-effective to just buy 100-pack of strips for 5-10 USD. The ones with 4 color-code gives enough variation to easily decipher vs 2-color options. .5 pH is good enough resolution to see if something is going off kilter. The cost of callibration fluid, hassle of keeping and storing said fluid, and the delicate nature of the probe means it will cost more and come with greater hassles/effort. Even if it adds up to 1-2 dollars less per 10 years, the convenience of single-use strips is worth it.

Ffs, look for yourself if u don't belive be https://dutch-passion.com/en/blog/a-visual-guide-to-cannabis-deficiencies-n987#calcium👈