Heya guys, got some easy ryder (autoflowering) about 2 weeks into flowering growing in soil (and perlite) under 600w hps. Fed every other watering with the canna range (2ml rhizotonic, 5ml flores, 2ml vega, 2ml boost, per litre). Had two plants look like the symptoms of nute burn, but the rest look nice and healthy. On the poorly looking two, the lower leaves have gone a pale green, and some leaves on top are crispy yellow with plenty of yellow spots and yellowing veins. My water is simply mains water, with a ph of 7. With all the nutes added and a bit of lemon juice the ph remains around 6.9. I added 2 litres of plain water and measured the ph of the run off, and it was 5.3 (!?!?). A couple of questions - how do i raise the ph of the soil? - what is draining the ph so much? thanks.