thats good wolfweed. just the ph water for now. water in a small spiral from the stem towards the edges. thankfully it is hard to over water coco due to its abilities. What is the R.h of the room without the domes on ? . could u hang a wet towel up with a bucket below to catch drips ? , this can be a good alternative to a humidifier as once the leaves get big and bushy , the rh becomes harder to keep low.
They should be old enough to stand the climate better now too but be ready with a support stake in case they tey to topple. gentle air passing them and making them sway a little , will help to strengthen the stem at this stage too. tey to keep the light fairy close so they dont stretch up too much can give them a better start as well.
journal needed mate so we can follow you on this for support.