Leaf tips have started going white but only on the the first set of leaves that came through not the new ones, also a bit of discolouring on them. I'll put up some photos so you's can see
Yer I'm giving them flora Nova grow, calmag, roots excelurator and amino acid at the recommended doses but when the tips changed colour I started feeding at 1/4 strength of the recommended dose is that why the new leaves haven't been burnt
What soil are you using? You don't need to give them anything for the first few weeks with most soils. Also, How frequently are you watering and feeding?
If you've not been feeding them long with nutes and the problem isn't spreading to the new growth then just keep an eye on them for the next few days. If it gets worse then come back and post then I'm sure someone with experience using coco will be able to help. Sorry I couldn't help dude.