So is my pen shot? Why did the ppm go from 797 to 696 in the final measurement i took? I normally just measured after adding everything to the gallon, but this grow i decided to measure after each individual nutrient i added to a gallon. I been doing this since week one of veg to week 1 of flower and it always does this. I'm not sure if this is normal (my spidey senses tells me it's not), or if my pen finally shot its wad?
is your ppm reader reliable/calibrated? I've seen ppm going down a little bit (maybe 10-20ppm) when using pH UP, but never seen ppm dropping that much after adding more nute.