that plant should be at 900ppm tops. more does NOT mean better in this field. clone start at 850, TWO (2) weeks later change and go at 900-950, then one week change and go to 1000-1050, then start flower stage at 1050-1100, then topping out a 1200-1250, and absolutely below 1300. NEVER go past 1300, ever. The problem you have is the plant grew faster then the stems could keep up. Like a kids bladder, it just does not have the capacity to hold as much urine as it takes in, and in turn it wets in its sleep. less is more in this field. more water and less nutes.