Quick PPM Question

say i want the ppm at 200
and the water im using already has a PPM of 100
do i add 200PPM worth of nutrients
or 100 PPM of nutrients to make the required 200 PPM

You can do a search for a water analysis in your area to make a good educated guess with or the right answer is you need to get a water analysis done.. The rule is to use the 100 that comes with your tap water into the equation, so then you would add only 100PPM of nutrients. What growing method by the way 200 is a low starting point, hard to hold PH, very dependent on how you are growing though.

well it says 100-200 ppm for clones and starting, then 200-400 second week, 300-600 third, 400-800, 600-1000 ect, so you mean if the ppm of my water is 200 i dont add any nutrients or, i dont understand

I don't use nutrients during cloning even though the bottle says I have to. The problem is we like to run clones a bit warmer, which leads to "unwanted growth" fungi/bacteria and etc where nutrients will feed this. Also starving them a little makes the roots strike out for food. But this could all be TERRIBLY wrong without knowing your cloning method. I use an Aero NFT cloner made of a rubbermaid that just sprays water on the roots, no dome, no nutrients and never anything but a razor blades and tap water.

P.S. Reverse Osmosis is a different subject, my answer is on tap water.

You would add 200 ppm to the 100 ppm water to have a total to 300 ppm

closet farmer has it right. subtract hard water ppm.

also, go extra light on the clones and shit. lots of companies say to add shit but i find it best to add nothing until rooted.

you want your total ppm to be @ 200 then you would only add 100 worth of good to your water..

consider yourself lucky if your tap ppm is only 100 om way up in the 5-600 range.. yuck!!