I have no idea what this means....... afaik hes been doing it a quite along while before me I think he has about 10 yr experience. He also agrees the difference between hydro and soil is minimal and noted that he just ended up with hydro because thats why he got sold on starting on and just kept with it. Evidently back when he started hydro was the new hotness.....Better look out if he ever gets his system dialed in......
A lot can happen in soil in 3-4 days.....you'll find out one day. It can happen faster in hydro.....Even the best of us get a hiccup once in a while !
Id suggest you do some soil grows and do a side by side yourself and compare it to your hydro with the same strain but make sure you have that soiled "dialed in" heh...I see this comparison everyday.