Feeding Question - transition to flower

These gals are over a week into 12/12 at this point. Do I need to start thinking about getting them some feed? They are in a mixture of FFHF and FFOF. The Volcano Girl on the right has been in the 3 gallon pot for about a month. The smaller ones on the left have only been in the 3 gallon pot for a little over a week. Do I wait for them to show some deficiency or try to head it off before it happens? I have Botanicare bloom nutes I can use or I can make up some banana peel tea if thats a better option.

Thanks in advance for any suggestions.

Any recommendations?

I am going to use the Botanicare Bloom with well water. I can also use RO with the bloom and cql mag if that is better. What EC should I be shooting for?

Just use the directed dose on the bottle , start half strength and work your way up to max.