I don't know about coir, but for soil I'd say your plants would enjoy larger pots.

g/l

Shovel
Shovelhandle Reviewed by Shovelhandle on . 5*White Widow feminized. Coco. Hello. I stared my first ever grow of anything really a while back will from now on log it here for you that might be interested. My setup is: 100*100*200 cm grow tent, Coco 7litre pots (might replant to 13 litre later). 125W LE Veg light for veg and 600W HPS for bloom. 280m^3/h ventillation (controlled by dimmer) and a table fan. Rating: 5