the only time i worried about pH in soil was once
the FFOF ran out of the powdered oyster shell buffer, into flower
i didn't have any dolomite lime, so to fix the incredibly low pH, i flushed until water was the same in/out, then governed my soil pH by controlling the pH in.
I think the oyster shell was leeched out due to my error, i added some extra perlite, and each time i watered i got a good amount of runoff that just kept sucking out the oyster shell.
the oyster shell got out before everything else, resulting in a low (5.0) pH.
after about 15 gallons of water in a 3 gallon container, things worked out and plants came back
having said that i never run into the problem now because i worry more about initial soil pH.
making sure you know what's inside the soil you buy is important.
if working with ffof i recommend using some dolomite
you most likely will never have to do a flush as said; closest thing to flushing the medium would be a monthly leeching, to clear salts off the roots.
i hope you measure soil pH correctly
https://www.rollitup.org/blogs/blog28487-ph-distilled-water.html
there's a method of compensating soil pH.
say you aim for 6.5 and you have 6.0, give it 7.0 this watering, recheck next watering.
say it moves to 6.3 now give it 6.7, see where i'm going?
people here i think are just trying to say, that your correction method is off, and you may be misinforming people
accurate pH isn't obtained by just measuring pH in and out.
make things easy, just use a recommended amount of dolomite when mixing your soil up, if it doesn't include it, instead of down the line flushing out the nutrients in the soil (which you may have paid for )
i water without pHing anything, I use a soil thermometer and match the water i give the plant to the temperature of the soil
sometimes pH is 8.0 from silica and no base nutrients
sometimes it goes down to 5.5 from no silica and some base nutes
after i water the leaves always "pray" which i forget what it actually means, but everything stays healthy regardless of what pH i give it, because the soil buffers my PH back.
i get that you are showing what happens after giving the plants the wrong PH for a while, but why would you be doing that?
the point (i think) that is trying to be made, is phing has it's place but you don't see it yet.
for a seedling, you dont use pH up, down, or anything
the baby is barely even using nutrients, pH is irrelevent (in proper soil)
it could grow to be up to a foot with no nutrients and just tap water (not too hard .. duh)
then you transplant it into it's new soil, where it will find new nutrients, and you continue to give it water, maybe rooting enhancer to ease the transplant.. whatever
now there is no need to change your PH... because you made sure your soil was properly prepared with dolomite (of course you put everything else in too, right?)
so what i'm saying here, is ph in out is most of the time unnecessary in soil.. it is this thing that seems important because you are told by certain people it is, but you need to understand that this low /high ph thing is going to happen in hydroponics
the FIRST thing i do when anything happens in soil, i think about what i've been giving her. I'd be crazy to be giving the girls such a high PPM dose that the solution drops down 2 points (remember, no pH down/up)
yes you are correct by saying you can fix by flush. but it's very unlikely someone screws up that bad
IMO the ph up and down are needed rarely, and the proper use is misconceived because of the way people tell others to use it.
the thread should be called "preventing pH trouble with proper soil " or something, get what i'm saying? these people are just tired of seeing this happen over, and over, and over (i think.. lol)
hey everyone, didnt you know, you dont have to bother check the ph of the water your using, Thanks for all the great advice on that!! Now look at those plants! This is my 2nd ph problem with this grow, and I have to thank you guys!! this is what I get for even giving you the thought that maybe, maybe the soil just might buffer back to 6.5. Not all soils will do this and this is fact.
