I didn't see the bit that said you had issues....whoops! :stoned: I thought you were just asking if 300ppm was likely to cause problems. I guess it depends on what is in those 300ppm's that makes the difference.

I know what you mean about the brita filter not touching the ppm, I tried it and dropped from about 512 ppm (0.8 EC x CF of 640) to maybe 500 (0.78 EC), so brita filters don't really do much for overall ppm.

Hey johnny123, I see you are in England too, maybe the water has more useful impurities here, and works better for growing? I guess without lab analysis we can't be sure.

Hope you manage to sort out your issues bertoxxulous! :thumbsup: