Calcium issues?

[oldskol4evr]

Yeah sorry I just had a brain fart haha. I meant runoff not ro, 2 different things haha, I'm trying to get my runoff to around 400 ppm

there you go,i mean you could just use the ro water with 1.5 ml cal mag in and flush that way,but your looking at way much more flushing,400 is were your plant needs to be so that why i said that number.