Soiless mix runoff PPM question??

What would be considered too high of a ppm for the runoff from a soiless mix?

I took a reading on some plants that weren't looking too good, I thought it was a P def at first, so I slammed it with flowering nutes. pH = 6.6-7 depending on plant, and the PPM was like 1500 which I thought was way high, I flush the shit out of my plants until they were about 350-650 PPM on run off. My tap water is about 150 PPM Ca, Mg, Fe, and S.

Do I do the right thing in thinking that 1500 (one was actually 2000) was really high or is that normal????

The tap water is well water btw, untreated, 150 foot deep...

wow really...

I found this on another forum, hope it helps as there aren't a ton of answers here, maybe it'll help someone later:

"I'm merely a parrot here........my hydro guy says you can check runoff and determine IF you need to flush by the numbers (he says he usually will flush with a number around 900ppm) and then AFTER flushing he likes the ppms around 300 so Reaper you don't try to be as exact with it as with hydro. My understanding of this is that its much more for overnuting than ph in this case........but he SWEARS by it.

I agree Stink.....most soil growers DONT have e.c. meters to measure that stuff with. And while YOUR eagle eye (and eagle tongue ) may be able to see when something needs flushing etc....NEWB soil growers like me need all the help we can get. "

What are you growing in? Promix?
nutes? pots size. we need to know more to help you.

I am growing in happy frog with 15% perlite, couple of handfuls of stone dust, dolomitic lime, and wood ash. Nutes being used: Jacks Classic (10-30-20) and molasses, once in a blue moon some epsom salt for extra mg. That is about it.

Molasses with a soiless mix? Why?

Bolster trace nutes, and pump carbs into the microbes so the plants can eat their shit (literally). Also a lot of the plants are in late flower, and the general consenus is that blackstrap molasses is just as good, if not exactly the same as those "carb booster" additives, for 5 bucks.

So I throw some in every couple of feedings...It hasn't been a negative.