PH and TDS readings - interpret please

@Myfriendis410 @MrPeat @dbrn32 my TDS meter (HoneFoest-white) was delivered and I calibrated my Mr Meter PH-100 pen. Straight tap water PH 7.56, PPM 230
After nutrients mixed. This is week 7 mix of FF trio to 1/2 gallon:
Big Bloom 7.5ml, Grow Big 5.0ml, Tiger Bloom 5 ml plus CaliMagic 7.5ml
PH 6.43, PPM 1460 and CM 3253
Run off readings: PH 6.58, PPM 2379 and CM 5061
Applied to WWA in 3 gallon pot, primarily FF Ocean Forest with compost, coco and perlite
Same mix as my Amnesia Haze which I burned up - see Very Ugly Sisters and previous WWA grows which were fairly successful for a first timer.
As far as I know, the PH going in is OK (acceptable range is 6-7, ideal 6.5). I’m clueless as to the significance of PPM in or out, other than it is a measure of the amount of stuff in the water.

So in a completely inert stripped media what you put in would come out. Any difference in ph out vs ph in shows you which way your ph is trending. Same goes for ppm really, but if you’re watering to a decent amount of runoff you should get at least what you put in to come out. Any additional would be solids that were already there.

I’ll be honest, most of the experienced growers I know don’t regularly check their runoff unless they are troubleshooting an issue. But it’s good for newer growers to get comfortable doing and tracking their results. Then if you see an issue in your plants you should have some historical data to reflect on. It’s also a lot easier for us to help then too.


Ok @dbrn32 will monitor a couple of waterings with and w/out nutrients. PH n mid 6 range is what you recommend for soil? You read different sources and, you know, each source has different recommendations.

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Ya sounds right. The issue is that different brands are made up differently. I usually amend my sole with a little dolomite lime and water in between 6 and 6.5. Depending on what I’m mixing if it falls between there I’ll let it ride. If I have to adjust I’ll see to something like 6.2 or 6.3 unless circumstances seem otherwise.