hi, I am growing 4 plants in coco in 6l square pots. It is canna coco pro and about 1 inch of clay pebbles on the bottom. Plants are 15 day old. I was going to flower them small inn the same pots, but now I can see some roots coming out of drain holes. should I transplant to bigger pots (it would be a problem due to space) or can I live it as it is? thanks in advance