i would start them off with 1/3rd strength nutes then each water change bump them up by 1/3rd so by the 3rd change or day 30 if you change nutes every 10 days you should be on full strength nutes.
then monitor if the EC/PPM levels are rising or dropping. If the EC rises it meens your ladies are using more water than nutes, so next time you will want to lower the nutes and monito them again then vise versa. Eventually with some trial and error you will get them drinking and eating equal quantities of Nutes and water.
I hope this helps