This is just a thought...depending on the type of ph pen u are using some have to be multiplied by 10...so if u had a 250 reading that actually would be 2500 ppm.It is most certainly a sighn of nutrient burn.I also have a producer and i have had fantastic yields .However i use the advanced nutrients that they provide as it has been tested with the box time and time again.Yields of AK-47....2pounds 1 ounce.Decent considering some people figure u can only get 1 pound out of it.