How to test soil run off?

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Venus32

Venus32

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Hello

Former outdoor grower here who feels like she’s having to learn everything again since starting to grow indoors!

Right, I’ve got a plant that’s limping through it’s grow. I suspect salt build up in the soil. I’ve had a range of f**k up’s
I’ve just invested in a PPM meter. I don’t really know what I’m doing. Should I be testing the ph and ppm of the run off to get a baseline before feeding again? If so, what should I be looking for?
Thank you!
 
AlexGrowns

AlexGrowns

190
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Yeah totally, give it just water and test the runoff PPM's if your feeding it 1000PPM's and 1600 runs out the bottom that's prob bad... I wish I had more specifics of numbers and ranges but now that you have the meter why not measure everytime and when things start to get funky ull see it on the meter ish? Have you been watering until like 20% runoff normally... I guess if you run just water and get a reading of the runoff and remeber how much you put in and post it pple will prob be able to tell you if it's that or not, pics help also if you can.
 
Dub_City405

Dub_City405

919
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If you are growing with soil. Simply flush it with just PH water a couple feeds then start a new week giving nutrients. You need to invest in microbials to help build up the roots to store the necessary food it needs to survive. If you run into a problem the best thing to do is flush it and start again. And when i say flush it that means just 1 or 2 times give it water with a bit of runoff.
 
growsince79

growsince79

9,065
313
Hello

Former outdoor grower here who feels like she’s having to learn everything again since starting to grow indoors!

Right, I’ve got a plant that’s limping through it’s grow. I suspect salt build up in the soil. I’ve had a range of f**k up’s
I’ve just invested in a PPM meter. I don’t really know what I’m doing. Should I be testing the ph and ppm of the run off to get a baseline before feeding again? If so, what should I be looking for?
Thank you!
You should check the ph for sure. PPM doesn't mean much in amended soils.
 
growsince79

growsince79

9,065
313
Yeah totally, give it just water and test the runoff PPM's if your feeding it 1000PPM's and 1600 runs out the bottom that's prob bad... I wish I had more specifics of numbers and ranges but now that you have the meter why not measure everytime and when things start to get funky ull see it on the meter ish? Have you been watering until like 20% runoff normally... I guess if you run just water and get a reading of the runoff and remeber how much you put in and post it pple will prob be able to tell you if it's that or not, pics help also if you can.
Thats true for hydro-no so with amended soils. I can feed 600ppm, get a runoff of 1200ppm and the plants will starve to death.
 
AlexGrowns

AlexGrowns

190
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Would that mean ur dumping 600ppm of salty acids? Seems like a lot, not arguing or anything just have had different experiences, I run 1100 ppm for a long time then cut it... maybe it builds up or stores differently?

Edit:l and plain water every second time or 2 waters one feed... not a pro by any means but I've never run into that specifically.

Thanks for the input.
 
growsince79

growsince79

9,065
313
Would that mean ur dumping 600ppm of salty acids? Seems like a lot, not arguing or anything just have had different experiences, I run 1100 ppm for a long time then cut it... maybe it builds up or stores differently?
New bags of ffof and cocoloco are over 3000ppm when flushed with straight water. The organic amendments don't measure the same as synthetic nutes. Its apples and oranges. Kinda like 25C is hotter than 50F.
 
mancorn

mancorn

1,260
263
Hello

Former outdoor grower here who feels like she’s having to learn everything again since starting to grow indoors!

Right, I’ve got a plant that’s limping through it’s grow. I suspect salt build up in the soil. I’ve had a range of f**k up’s
I’ve just invested in a PPM meter. I don’t really know what I’m doing. Should I be testing the ph and ppm of the run off to get a baseline before feeding again? If so, what should I be looking for?
Thank you!

It depends on what type of fertilizer you’re using. With organics (which is primarily slow release) in soil, your EC/PPM can’t be tested with a PPM meter. (Well, it can be tested it just doesn’t mean much in relationship to your nutrients.)

if you’re using salt based fertilizers (most bottled) you should do a pour through test https://www.extension.purdue.edu/extmedia/HO/HO-285-w.pdf.

The best use of your meter isn’t the actual numbers, but how the numbers change over time. In general your PPM should be less that what your feeding, as your plant should be consuming nutrients. So if you feed at 600 and testing 400 you know your plant is up taking properly. If your PPM out is way lower then your input, than your plant is not getting enough food and you can increase your feed. If your PPM out is higher than your input, then your feeding too much and nutrients (salt) are building up and you’ll need to flush out the excess.
 
Last edited:
Venus32

Venus32

63
18
Yeah totally, give it just water and test the runoff PPM's if your feeding it 1000PPM's and 1600 runs out the bottom that's prob bad... I wish I had more specifics of numbers and ranges but now that you have the meter why not measure everytime and when things start to get funky ull see it on the meter ish? Have you been watering until like 20% runoff normally... I guess if you run just water and get a reading of the runoff and remeber how much you put in and post it pple will prob be able to tell you if it's that or not, pics help also if you can.
Thanks for that. I’ve only just started watering again normally since an overwatering error. Hence I don’t like to soak the soil but do get some run off, just not much. I want to feed it but want to get an idea if it needs feeding first. And the ph level. Just never done either before!
 
Venus32

Venus32

63
18
If you are growing with soil. Simply flush it with just PH water a couple feeds then start a new week giving nutrients. You need to invest in microbials to help build up the roots to store the necessary food it needs to survive. If you run into a problem the best thing to do is flush it and start again. And when i say flush it that means just 1 or 2 times give it water with a bit of runoff.
Thanks, that’s helpful.
 
Venus32

Venus32

63
18
It depends on what type of fertilizer you’re using. With organics (which is primarily slow release) in soil, your EC/PPM can’t be tested with a PPM meter. (Well, it can be tested it just doesn’t mean much in relationship to your nutrients.)

if you’re using salt based fertilizers (most bottled) you should do a pour through test https://www.extension.purdue.edu/extmedia/HO/HO-285-w.pdf.

The best use of your meter isn’t the actual numbers, but how the numbers change over time. In general your PPM should be less that what your feeding, as your plant should be consuming nutrients. So if you feed at 600 and testing 400 you know your plant is up taking properly. If your PPM out is way lower then your input, than your plant is not getting enough food and you can increase your feed. If your PPM out is higher than your input, then your feeding too much and nutrients (salt) are building up and you’ll need to flush out the excess.
That’s the best explanation I’ve heard, thanks.
 
Dub_City405

Dub_City405

919
143
You feed on a regular weekly basis. Once a week twice a week how ever much YOUR plants want. You just have to find that pattern. Start out with water then gradually give little nutrients at a time then gradually increase. But genetics is where the outcome really comes from. You give it just a bit of water a bit of nutrients and some light and fresh air. The plant will do the rest.
 
Venus32

Venus32

63
18
You feed on a regular weekly basis. Once a week twice a week how ever much YOUR plants want. You just have to find that pattern. Start out with water then gradually give little nutrients at a time then gradually increase. But genetics is where the outcome really comes from. You give it just a bit of water a bit of nutrients and some light and fresh air. The plant will do the rest.
But it looks like this 😕 and I’m worried about feeding a plant that is only just recovering from overwatering. That’s what I think I’ve read - I honestly don’t know anymore!
F3DA3F41 43FF 4D1F 837D 0BD7CAF94A0E
B092E341 8610 4BFF AB72 2E75C5C0C328
 

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