3 part nutrients and ppm

I am using the advanced nutrient s 3 part non ph perfect nutrients, and tap water. What im wondering is, when i check my ppm reading and I need to add nutes, how do i know of which nute to add?? or do i mix them all at an equal amount to get my desired ppm?? What if my tap water already has a ppm reading of 250 ish?? Also wouldnt the ppm of the nutrients that im adding totally change when i add to the resevoir because the ppm of the res water is different then what i am adding??? How does the math work??

i used to work myself to death on topping a res, but learned over time it is much easier to have as big of a res as you can and just let the plant use it then start over. i never add nutes to a res after its used.

I am starting my first DWC right now as well, and from the research I have done, and how I am going to do it is the same as superstoner1 said. I am going to mix up my nutes for the week, and only top off on fresh water in my buckets. I plan to change the nutes each 5-7 days. This plan, like all my change of course depending on how the plants are reacting, but I have read from several people to do it this way. This keeps DWC simpler, and later on down the road I / you, can experiement more with topping off the nutes in between changes.

But I like the question about the tap water, as my PPM on strait tap is 350, so thats an awesome question as to where to start your baseline, at 0 or at the current tap water reading.

my tap is 110ppm, it is included in my total ppm. i keep dwc at 600 and aero at 800-1000.

If your water is 250ish, consider the hardwater formula. That's if your hardness is calcareous. If you have sodium in your water, no good can result, and you're best off with RO. Jmo. cn

pretty sure its calcium. sometimes i get a white residue on my dishes, which i think is calcium

If it's municipal and not local well water, you can get the local water analysis either online otr with a phone call. It's a good thing for every grower and gardener to know imo. cn

Good to know. i'll for sure check that out. not a well. I pretty much live right downtown