Runoff PPM

[The_Core]

Anyone have any experience measuring the runoff PPM of pre fertilized potting soil and knowing when exactly to start running nutrient solution? How is this done? How do you calculate when and how much nutrients to start adding to the water?

I have a BlueLab combo meter so if anyone can offer some advice I would appreciate it. Thanks.

 

[The_Core]

I didnt get any responses so i did some more looking around. I guess the best I can do is this. I use a Stealth RO. My water comes out at about 10 ppm and 7.5 PH. I will adjust PH to 6.5 and water my plants. Collect the runoff, measure the PPM That will tell me how much nutrient strength is coming out. Then I will water with 10 ppm nutrient solution and see how much comes out and keep increasing until gradually until the PPM's in the runoff say what? 300 PPM for seedlings correct? Any input is appreciated.

 

[Grower4life]

That sounds rite, For the most par that's what I have done in the past. The soil I use has about 300 ppm to start with so I plant the rooted seedling (rooted in 1.5x1.5 grodan rockwool cube) ( so seedling is a bout 2.5 inch tall and one nice tap root through the bottom) anyways I water with 6.5 ro water maybe 3 or 4 times and then I water with 300 ppm of grow, cal mag, liquid karma, diamond nector ph 6.5. then ro 6.5 water, I just watch for a lil yellowing and then feed again.
Hope this was helpful , cheers

 

[joe fresh]

look in my sig

 

[The_Core]

That sounds rite, For the most par that's what I have done in the past. The soil I use has about 300 ppm to start with so I plant the rooted seedling (rooted in 1.5x1.5 grodan rockwool cube) ( so seedling is a bout 2.5 inch tall and one nice tap root through the bottom) anyways I water with 6.5 ro water maybe 3 or 4 times and then I water with 300 ppm of grow, cal mag, liquid karma, diamond nector ph 6.5. then ro 6.5 water, I just watch for a lil yellowing and then feed again.
Hope this was helpful , cheers

Thanks Grower4life! So what your saying is that you start with soil that already has a starting runoff of 300 ppm and then you water 3 or 4 times with RO 6.5 PH water, then you mix up a batch of nutrients that puts you at 300 PPM, then you give them a feeding, No issues with burning from too much nutrients?

 

[The_Core]

look in my sig

Ok Thanks I will have a look now.

 

[The_Core]

I guess what I am trying to understand, and maybe i am missing the point completely, is that the medium that we use to grow our plants with, if its pre-fertilized how do you know the strength of the fertilizer and the ppm that is translates into? The feed charts for various fertilizers say use this ppm and that ppm and telling everyone what is best. Lets say i have a home made recipe of soil, and the fertilizer I am using is biobizz. Well biobizz says with their all mix soil from week 1 you should use 2 ml per liter. Well that may work great with the soil that they used the calculations for, but what about MY soil. How can i tell exactly how many ppm's of nutrients are in the soil so i know how much to add. I am really confused on this subject.

 

[joe fresh]

I guess what I am trying to understand, and maybe i am missing the point completely, is that the medium that we use to grow our plants with, if its pre-fertilized how do you know the strength of the fertilizer and the ppm that is translates into? The feed charts for various fertilizers say use this ppm and that ppm and telling everyone what is best. Lets say i have a home made recipe of soil, and the fertilizer I am using is biobizz. Well biobizz says with their all mix soil from week 1 you should use 2 ml per liter. Well that may work great with the soil that they used the calculations for, but what about MY soil. How can i tell exactly how many ppm's of nutrients are in the soil so i know how much to add. I am really confused on this subject.

let the plants tell you what they need..i grow in promix and feed everytime...

feed charts are for the water.ferts you pour in, not what comes out in the runoff..

to be honest my runoff is always above 2000ppm, but i always feed @ 600-750 ppm....so worrying about ppm in runoff isnt a great deal unless your having a huge problem and cant figure it out...then this is a great method for narrowing down your problems

 

[papaduc]

let the plants tell you

I was just about to say the same thing.

Learn to grow based on what a hungry vs overfed plant looks like.

Your question: how do I know when to start feeding if my soil is pre-fertilised?

The answer is simple. Watch the bottom leaves of your plant. As soon as you notice the very bottom begin to pale, that is when the plant has used the stored nutrients and you should either begin feeding, or pot up into fresh compost.

 

[The_Core]

Thanks for all the help. I will focus less on the PPM of runoff and just worry about the PH. I have the full BioBizz lineup. I will start with a very diluted feeding and go from there!

 

[SRGB]

The Core:

Runoff PPM
Anyone have any experience measuring the runoff PPM of pre fertilized potting soil and knowing when exactly to start running nutrient solution? How is this done? How do you calculate when and how much nutrients to start adding to the water?

I have a BlueLab combo meter so if anyone can offer some advice I would appreciate it. Thanks.


Hi, The Core.

The experiment that you are attempting to perform might include several factors. Depending on the media and substances employed, the `run-off``ppm` could vary substantially. The readings, also, might not actually reflect the chemical composition of the `nutrients` held on the collidial surfaces of the media, nor the discreet chemicals within that run-off.

Some substances might dissolve, or become soluble at very different concentrations in relation to the other chemicals within the media. As an example, calcium might precipitate, or become more insoluble if contacted by other chemicals. iron might become less soluble at higher (more alkaline) pH ranges. These substances could be read by a `meter` as xyz `ppm`, yet might be fully insoluble (plant roots virtually incapable of assimilating the chemical through cation exchange).

In any event, a very good experiment to proceed with. Accurately listing each item within regime might be helpful, as then a gardener could reference the solubility properties of those individual components. Listing the media might also help determine how well the media drains, or inversely, how much potential solution might be still stored within the media (that portion that did not drain out, or did not form `run-off`).

To compile accurate data sets relevant to which discreet chemicals or compounds were within the `run-off`, an experimenter might consider examining `millimhos` instead of `ppms`, to attempt to precisely determine the actual physical weights, or molecules of discreet chemicals within the `run-off`. Perhaps involving more math, but perhaps deriving more accurate numbers.

We have done a fair amount of experimentation with using the `run-off` as a measure of when to water, but within a different template; namely, inert rocks as a medium, synthetic nutrients, and never `dumping` the `run-off`.

We wrote an article on our experiments and findings at the SRBGB subforum, which might be helpful:

Square Root® Brand Garden Bag - Drain-To-No-Waste [Methods].

The basic premise being that the specimen only actually required x amount of water (or, nutrient solution) per period (for example, 24-36 hrs), and that the run-off from that solution application could be immediately re-used by the specimens` roots, thus eliminating virtually all `waste` from the system or method. The run-off level, if kept at a very minimal level, could also become the primary signal from the plant or tree to the gardener as to when the specimen actually required more water (or nutrient solution). One of the goals of the exercise being total reduction of `waste`, both of actual water and actual nutrients, without ever `over-watering` the specimen.

We have employed similar approaches when experimenting with SRBGB`s using only `organic` compounds or nutrient solutions, and the results were similar to those of inert media and synthetic nutrients. From what we could gather, pH (both of the water applied and the discreet chemicals or compounds within the media, and/or of the applied solution) might greatly influence the solubility of the given compounds. Merging an assortment of compunds without cursory awareness of their potential to precipitate might result in inaccurate readings. A given compound might be present as to `ppm` or `EC`, yet it might be partially or even fully insoluble as to plant or tree roots.

A solution might be to lightly top-dress the desired nutrient, organic compound, etc., then apply pH balanced water based on those specific compounds, in order to render them more soluble. Given such an approach, the `run-off` might become less important, as each watering would be tailored to the specific elements or compounds provided at that nutrient delivery. Unless the run-off was to be further used by roots after exiing the container, in which instance the gardener might attempt to regulate the run-off to only a minimal amount, so that it would be uptaken (or, more appropriately, perhaps, `exchanged`) by the plants` roots; 24-36 hours being a modest amount of duration for full depletion of the run-off, within that brief span chemical reactiveness of that run-off might be minimal (pH stablility) .

Yet another option might be `organic`, if that were the gardeners` prefernce, CRF, or controlled release fertilizers,, which might gradually release nutrients over an entire season.

Excellent experiment, again. We hope that this post might be helpful.

Best,
/SRGB/

 

[papaduc]

Thanks for all the help. I will focus less on the PPM of runoff and just worry about the PH. I have the full BioBizz lineup. I will start with a very diluted feeding and go from there!

With biobizz grow or fishmix, start on 1ml per liter when you see the very first sign of paling in the lowest leaf.

 

[The_Core]

With biobizz grow or fishmix, start on 1ml per liter when you see the very first sign of paling in the lowest leaf.

Thanks papaduc, I will do that. I cant follow there feed chat for biobizz seedlings because I am not using there all mix. So if i try to follow their feed chart I might just burn up my seedling. Thats why i was trying to do the runoff PPM test to calculate the nutrient strength of the soil by itself but its a very complicated process i will probably wait on until i have more knowledge and skill.

 

[papaduc]

The only knowledge you need is what is a good compost to start seedlings in.

If you really want total control of what's going in from the very beginning, just switch to coco. Otherwise, trust your seed mix and let your plants tell you if something is wrong.

Just use plain water to feed them and don't get stupid amounts of run off or you'll leach the nutrition from the soil. For that reason alone you really shouldn't be doing run off tests on fresh potting soil which has seeds in. You can do a simple extraction method to find out bits of what you want to know. But when seeds are in the pot, just water them gently and keep it really basic.

You grow in soil for a reason - so there's none of that messing with pens and potions. Like I say, if your curiosity is your Achilles heel, switch to hydro.

I grow in coco and check ph and ec, but even I don't bother with run off unless I'm testing a small sample of new freshly expanded coir brick. that's the only time I need to know what the figures are. Once the plants are in it, that gets forgotten.

 

[The_Core]

The only knowledge you need is what is a good compost to start seedlings in.

If you really want total control of what's going in from the very beginning, just switch to coco. Otherwise, trust your seed mix and let your plants tell you if something is wrong.

Just use plain water to feed them and don't get stupid amounts of run off or you'll leach the nutrition from the soil. For that reason alone you really shouldn't be doing run off tests on fresh potting soil which has seeds in. You can do a simple extraction method to find out bits of what you want to know. But when seeds are in the pot, just water them gently and keep it really basic.

You grow in soil for a reason - so there's none of that messing with pens and potions. Like I say, if your curiosity is your Achilles heel, switch to hydro.

I grow in coco and check ph and ec, but even I don't bother with run off unless I'm testing a small sample of new freshly expanded coir brick. that's the only time I need to know what the figures are. Once the plants are in it, that gets forgotten.

I didnt even think about that. Your correct. Extracting a soil sample would have been alot smarter instead of pushing a ton of water through fresh soil to measure PPM and therefore rinse half my nutrients out the bottom. I will stick with this soil grow and then switch to coco. I have been considering coco for some time and maybe thats the better option so i know exactly whats going in, and whats coming out. I live in Europe and the country I live in has 1 store that sells the supplies I need and they are about 5 hours away. So for me I had to purchase commercial brand fertilized garden soil, i mixed a ratio of 1-1-1, Soil, Perlite, Vermiculite, and some Mycorrihizal powder. Seedling looks ok I just heat stressed it for the first week so the first set of true leaves browned slightly on the serrated leaf tips and cupped a tiny bit. We will see how it goes.

 

[Hash Zeppelin]

https://www.icmag.com/ic/showthread.php?t=11688

https://www.icmag.com/ic/showthread.php?t=231387

^I cant thank Stitch, and Joe fresh enough for posting up those guides. I use them all the time. I print them out and give them to patients that do their own little gardens too. I used it last week in combo with help from the people from the site to get my plants back on track.

 

[The_Core]

https://www.icmag.com/ic/showthread.php?t=11688

https://www.icmag.com/ic/showthread.php?t=231387

^I cant thank Stitch, and Joe fresh enough for posting up those guides. I use them all the time. I print them out and give them to patients that do their own little gardens too. I used it last week in combo with help from the people from the site to get my plants back on track.

Thanks Hash Zeppelin, I am going to check that out now.

 

[The_Core]

Here is my Azacur freebie on my test run. Commercial garden soil amended. Its a 1/1/1 ratio of soil, perlite, vermiculite and Mycorrhizal powder. I Use a Stealth RO water purifier which brings my tap that is at 8.0 PH and 80 PPM, to 7.5 PH and 10 PPM. Right now i use no fertilizer just PH adjusted RO water with superthrive. Daytime temps are holding at 73-76 and nighttime dips to about 68. I use a while poly grow bag, an 8 bulb 2 foot T-5 AND 2 clip air king fans for air circulation. I was running a heat mat but not needed any longer. It was heat stressed quite a bit at fist due to my fuck up and is off to a slow start. This is a freebie seed, regular sex, don't know if it is female or male. If its female i will grow her out a bit larger and then use her for clones, its its male its getting cut. Anyway its in a secret Jardin propagator tent at the moment.

 

[joe fresh]

hey core...

if ur tap is 80ppm, there is no need for the RO...80ppm is plenty perfect, infact at 80ppm your going to need to add cal/mg, my water is 170ppm from the tap...used RO, but now my RO machine just sits in the corner, i noticed to many deficiencies while using RO water...

 

[The_Core]

hey core...

if ur tap is 80ppm, there is no need for the RO...80ppm is plenty perfect, infact at 80ppm your going to need to add cal/mg, my water is 170ppm from the tap...used RO, but now my RO machine just sits in the corner, i noticed to many deficiencies while using RO water...

Joe Fresh thanks for the info. That makes sense about the cal/mg. So stick with the 80PPM water and just PH Adjust? You don't think I will run into any issues? How should I adjust my BioBizz lineup when I start to fertilize? Will the 80 PPM effect my dosage? I usually let my water sit for many days to dechlorinate. Anyway let me know what you think, everyone stresses RO water is that only for Hydro setups and maybe coco? Thanks again.