So I've begun to train my plants with LST after a month from seed. Some plants are more developed than others, one isn't tall enough to begin training compared to the others. Now that I'm getting some smell from the tent and they've been developing in their 5 gallon fabric pots I've decided to try out giving them nutes. I'm using Growth Technology Grow and on the label it says to add nutes to water of 1.5 mS/cm. I am using this TDS pen after a GC member recommended it to me to use with UK tap water. I used the following website to convert 1.5 mS/cm to 960 ppm TDS. Conductivity convertor, Siemens into TDS PPM and MHO So I stick the reader in and it gets to 621. When I add nutes it jumps up and so I begin to water it down. The reading I get is something like 005 with a x10 underneath. EH?>!?!?!?! So I am guessing it's 1005 ppm TDS so I think that I just need to water it down a little. So I add water in tiny bits at a time and it goes like this 005 004 003 621 Is my TDS meter broken or am I totally missing something? The nutes are obviously very strong but diluting with water has a much more accommodating margin for error.......... however with the way it was watering down you'd think I was adding in tons. The huge jumps are making no sense and are really doing my head in as maths is something I don't find hard........... I reset the test by adding another 500ml of water to bring the concentration down. My readings were adjusted with a 1/4 teaspoon of nute. 530 550 + 1/4 tsp 577 + 1/4 tsp 609 + 1/2 tsp 003 (x10 underneath reading) If this is metric it should go up to 999 right? When I search up TDS meters websites say they go up to 999......... someone please help as this is INSANELY frustrating.