EC/CF values in Ebb and Flow

[XIX]

Hi

Any tips on best EC or CF values in the different stages of growing chillies?

And do i retract the amount measured in the water, before i add anything to it, from the disired value ?

ex. clean water is 4 CF, and i want 20 CF. Is my target CF then 24. And does this transfer to EC also?

br. Martin