The only way to drown them is in organic media that is broken down, correct? I use all inorganic. Clay balls, hydroponic rock, lava rock. Large perlite and a little charcoal. I flush out the pots weekly and never let them sit in fertilizer.
What do you isn't accurate? How far off can it be? I use Peters 15-5-15 with calmag. I have a water test. Would you like to see it. I could send it Gmail. They told me people would love to have my water.
I have not been able to upload pictures on this forum. Any advice or tricks. Yes I do use a TDS meter. I was told it was supposed to be 600-700. The pH of my water is 6.5. I have had it professionally tested twice.