there is no standard, and this guy doesnt understand that ppms are up to your and plant. I could tell you that 2000ppm works but it may not for you. I run 300-400 in veg and most people use double that, but mine burn. WW also has many different cultivators for seeds, so there is alot of fluctuation between what your using. its trial and error. start low and build up. your nutes should have the suggested amount to use, go from there.