hey thanks keylime,

i am growing in hydroton clay pebbles, so the drain leaves it nice and dry with lots of fresh air sucked in around roots. i do like the stability given from a rw block but also see what ur saying- good idea removing as much rockwool as possible early on, will try that next time round. roots were developing well out the bottom though before potting, so im sure the roots are well into the pebbles now- i started them on one flood a day when first potted and have increased every few days to once every 3hrs.

i know i need a ppm meter to fully verify whats going on, like you say till then i am just guessing- never having one Ive always gone on the principle that using a 10% weaker solution than stated on bottle will keep the ppm within a suitable limit to prevent overfeeding during full feeding stage and starting with 25% strength when first introduced to system is usually weak enough. . am still new to canna a+b!

again thanks for ur feedback, was positive. first time ive had trouble in this area so was bit concerned. you've given me the push to order a meter, i know it is essential, with massive benefits.

peace out:thumbsup: