Need halp with ppm

Ok so I just fed my plants after 8-9 days since the last feed with one watering inbetween.
I water them 4 days ago on the 18th, with 100ppm cal-mag RO water pH at 6.2.
The run-off from the watering 4 days ago for both plants was around 750 ppm and 6.2 ph.

Take note, I did over-feed them accidently the last nute watering (8-9 days ago), and they encountered some nute burn. So I made sure the watering (4 days ago) was a good one to rinse them out a little bit.

Now for the main part, I just fed both plants about an hour ago.
I gave them about 10ml of pbp grow and 5ml of pbp soil bloom with 1ml of cal-mag and pH it properly of course. The ppm was around 950 going in after mixing everything into the jug and testing it.

*My plants are on week 4 day 1 of flowering. If that helps to know where my ppm should be at.

But... when I checked the run-off just a bit ago, the ppm was saying 140-160 x10?? So around 1600 ppm?
How is this even possible? I tested a second part of the run-off from the same plant and it dropped to 118 x10?
I don't get how it was so high to begin with, then dropped when I tested it again on some of the more "fresh" of the run-off water.

So then I fed my second plant with about 950 ppm going in, same exact thing?
The run-off was reading around 1500ppm but was still pH normally.

I was about to flush but I didn't want to panic, figured I'd come check here first.

Any ideas? I'm kind of confused about this one unless it was my ppm meter but I tested it and it worked just fine?

Hey man.

Medium??

Can I just confirm too.
1. You had previously over fed?
2. You fed 100ppm first time. Waste was 750?
3. You fed 900ppm today. Waste was 1600?


You say your meter is accurate, and that you tested it. So I believe you. Count it out for now.

Tim1987 said:

Hey man.

Medium??

Can I just confirm too.
1. You had previously over fed?
2. You fed 100ppm first time. Waste was 750?
3. You fed 900ppm today. Waste was 1600?


You say your meter is accurate, and that you tested it. So I believe you. Count it out for now.

Click to expand...

Sorry I'm growing in Happy Frog Soil with perlite, 70/30ish mix.

1. Yes, I fed 8-9 days ago and the ppm going in was "probably about" 1300-1400 (don't ask...) It was 20ml of botanicare pbp grow, & 1ml of cal-mag.
2. Then I watered them 4 days ago, with RO water with 1-2ml cal-mag and 100-150ppm going in, not much at all since I burned them from the previous feeding. That waste from when I watered them 4 days ago was around 700-750. (Roughly where it should be right around now 750-950)
3. Today I fed 950 going in, the waste was 1600.

Sorry I read my OP and realize it was kind of hard to understand, sometimes I don't make sense and go back n forth, my bad.

Project Ponics said:

Sorry I'm growing in Happy Frog Soil with perlite, 70/30ish mix.

1. Yes, I fed 8-9 days ago and the ppm going in was "probably about" 1300-1400 (don't ask...) It was 20ml of botanicare pbp grow, & 1ml of cal-mag.
2. Then I watered them 4 days ago, with RO water with 1-2ml cal-mag and 100-150ppm going in, not much at all since I burned them from the previous feeding. That waste from when I watered them 4 days ago was around 700-750. (Roughly where it should be right around now 750-950)
3. Today I fed 950 going in, the waste was 1600.

Sorry I read my OP and realize it was kind of hard to understand, sometimes I don't make sense and go back n forth, my bad.

Click to expand...

Nothing wrong with the post at all. It was full of the right information.

TBH I don't measure waste with soil myself. But if its working for you. I won't tell you not to.
It's info none the less. Consistent info too. So I think it should be reliable.

In a DTW hydro setup waste is a must.
I asked which medium it was. Because if it was coir the data speaks for itself. It could only be salt buildup.

If you do the math, like you have, and add the first waste to the second feed. It reads roughly the same, as your second waste reading. Minus a little because the plant has been feeding, soil absorption etc.
Looking at your data results, Imho is what it's showing.


As far as ppms, and organic material goes. I don't find it very reliable at all.
Mixing a soil sample with distilled water, then testing the ec is my preferred method.
Ec you're measuring salt content.
Ppms you're only measuring how much of ???? is in the water.

At 4 weeks into flower you should have fed twice as much bloom as grow. The way you did it is fine for up to the flip. You want to be lowering the amount of N they get at this stage and raising the ratio of P an K with more K than P as well.

The reason you got that high ppm reading was because you were washing out nutes in the soil with high ppm nutes and they added up. Had you used RO water it would have been a lot lower.

I don't bother with ppm for plants I grow in pots. Jug says 4ml/L and I feed every 2nd watering using RO with half that or less most times. And that's with soilless ProMix HP that has no nutes built in.

Tap water is crap most times and the minerals in add to the salts load in your plants.

Happy Frog soil has nutrients already. You don't need to add much unless you grow in small pots. Use big containers, plenty of soil, and don't add unless you're sure you have to.