You can get high ppms by letting the soil dry out too much, especially early when the plants don't consume much. Peat mixes have a higher CEC than coco and will retain some salts and minerals when it dries. I would suspect this is the root of his issue. And I don't doubt you, yet I had little problem with V2 and never added cal/mag to it, however without a doubt, some strains just want more. I actually liked V1 better as I controlled how much cal/mag I used.
And I doubt a little nutrient dried on the pots would have much affect, unless it was seriously caked on. I have auto pots that have not even had the soil removed or changed in them for almost three years, that were fed MC for most of those three years. I never flushed them either. No problems with salts buildup, and this is with soil, which you'd think would have a bigger problem with that than any other medium. I have no answers as to why, just my anecdotal data, but I'm thinking it's because auto pots never dry out during a grow and the nutrient levels stay consistent. I postulate that salts buildup is a result of way over feeding, like people running coco at 1400 ppms. Yep, its going to build up in the medium. at a ppm that is close to the happy medium for plant health, your not going to have that issue. Even in my small pots feed MC, I recycle the soil and do not flush it between uses. i merely water it during seedling stage, then right back to 500-550 ppms of MC.
I also doubt missing one feeding of cal/mag will affect the plant. He needs to get the PH under control, which is another area affected by the soil becoming too dry. The medium should still be slightly moist at watering time, not dry the point the plant would soon start to wilt. The drier the soil, the more the soil will skew towards acid.
And I doubt a little nutrient dried on the pots would have much affect, unless it was seriously caked on. I have auto pots that have not even had the soil removed or changed in them for almost three years, that were fed MC for most of those three years. I never flushed them either. No problems with salts buildup, and this is with soil, which you'd think would have a bigger problem with that than any other medium. I have no answers as to why, just my anecdotal data, but I'm thinking it's because auto pots never dry out during a grow and the nutrient levels stay consistent. I postulate that salts buildup is a result of way over feeding, like people running coco at 1400 ppms. Yep, its going to build up in the medium. at a ppm that is close to the happy medium for plant health, your not going to have that issue. Even in my small pots feed MC, I recycle the soil and do not flush it between uses. i merely water it during seedling stage, then right back to 500-550 ppms of MC.
I also doubt missing one feeding of cal/mag will affect the plant. He needs to get the PH under control, which is another area affected by the soil becoming too dry. The medium should still be slightly moist at watering time, not dry the point the plant would soon start to wilt. The drier the soil, the more the soil will skew towards acid.
