hey weedhound - ph is consistently btw. 5.5 and 6.1...i don't use a ppm meter, i use an EC meter, and the solution should be btw. 1.1 and 1.9 as I've been taught...have been keeping the solution at 1.3 or so, though it went down to .8 in 24 hours...i didn't think it was nute burn as the other two plants are absolutely fine...and they're getting the same water from the same NFT system...plants are growing in rockwool cubes...and the nutes are CANNA Aqua Vega A and B (instructions on the nutes tell me I should only switch to Aqua Flora at the first sign of flowers).

the mystery to me is that two of the plants look absolutely fine, but the tallest one doesn't, which is why i was thinking of bending down the top...

many thanks for your time and advice....