the way i do it is ,i refill my buckets to my desired level with plain water. my original ppms are 1000@ .5 conversion after a week my levels are around 800 ppms so i will now add nutes to bring my ppms back to 1000. i will keep doing this until the end. hope this helps.I was wondering about adding nutes when you top off water. Should you add new nutes everytime you top off water or just so often and if so how often because i hear its good to just top off water so the plant takes the nutes that it didnt take before?