Chip Green
Well-Known Member
Yes. I agree.
Tried my best to fix – Not looking good
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troutfarm
Well-Known Member
I would like to learn more about this. What information can I gain from ph out with regards to salt accumulation? Is it a comparison between ph in and ph out?
As the water goes through your medium it drags excess salts out with it and the runoff PH will be lowered by the excess salts / unused fertilizer.
for instance if you are putting 6.5 PH water in and you get a PH of 5 from the run off then you know there is significantly nasty build up of salts in your medium.
3rd Monkey
Well-Known Member
What Kenny said.
troutfarm
Well-Known Member
Ok, perfect, thanks for the info. That makes sense. So my next question would be what sort of a spread would warrant a flush, or other measures to remove excess salts? Over the past several waterings my ph in to out has dropped anywhere from 0.1 to 0.35 ph (as in, 6.7 in and 6.4 out, or 6.75 in and 6.65 out). Are these reasonable spreads? Or is it considered dangerous salt buildup with any discrepancy between ph in and out? I also measure my ppm in and ppm out, although many forum users here feel that ppm out is a useless number (but I collect the data anyway).
that is fine. Don't flush if that is all the PH spread you are getting.
When i have a plant that needs a flush...I put in water that tests almost green (7.0) and when it comes out it tests orange (5.5-5.0)
3rd Monkey
Well-Known Member
Va va voom. That's how it's done.
That's why I always laugh when people say testing runoff is a waste. Not if you know what you are looking for.
What would happen if the excess salt you have is in a carbonate form...magnesium carbonate, calcium carbonate, or potassium carbonate? Salts which contain sulfur have the potential to lower ph, but if it's say gypsum (calcium sulfate), or potassium sulfate, it won't affect ph either. Most elements that are bonded to nitrogen in nitrate form, will also not lower ph..with the exception being ammonium nitrate..or any salt which contains ammonium, will lower ph. That's why i can take gh flora micro, and it will have virtually no effect on my ph...even if i put it to say 1000 ppm. On the other hand, if i take the bloom and try that..it will lower ph by alot..because it contains phosphoric acid, monopotassium phosphate. Long story short, many salts, in excess, will not lower your medium's ph. By excess i mean sitting in your medium, not being used by the plant. If the plant takes up any cation in excess to toxic levels, then that would lower your medium's ph, but not if the plant does not use it.
I've had plants in the past that runoff showed 3000 ppm lol..yet my ph was right there, same as at the start, 6.3, 6.4ish.
3rd Monkey
Well-Known Member
Consider this, and you can test it, water ph normally raises the longer it sets as it releases carbonic acids, maybe not by much, but heads toward alkaline.
Personal example
Now, if this is the case and I water at 6.5, then again 3 times and my runoff the 3rd time is 6.3... I know I have excess salts in my medium. If it stays within 6.7-6.8, that's within reason because that's what my water raises to in a 48hr span. The rate at which I water.
So if my ph is at all low in a 48hr span, excess. If my ph is higher than 6.8, excess. With most nutes, it's usually low in veg, not always but more common anyway. Works for the high side too though.
Personal example
Now, if this is the case and I water at 6.5, then again 3 times and my runoff the 3rd time is 6.3... I know I have excess salts in my medium. If it stays within 6.7-6.8, that's within reason because that's what my water raises to in a 48hr span. The rate at which I water.
So if my ph is at all low in a 48hr span, excess. If my ph is higher than 6.8, excess. With most nutes, it's usually low in veg, not always but more common anyway. Works for the high side too though.
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Chip Green
Well-Known Member
Why not just measure the EC of the runoff?????
3rd Monkey
Well-Known Member
You should measure EC.
EC tells you how much the plant is feeding or in excess.
PH tells you what the plant is feeding on.
If the plant is feeding on nitrogen, your EC will tell you how much. Your PH will drop, which is how you know it's nitrogen.
If your plant is feeding on phosphorus, your EC will tell you how much.
Your PH will raise, which is how you know it's phosphorus.
Each measurement alone won't tell you much. It's just easier to start with ph since it's usually a ph problem anyway.
Both those measurements together, tell you how much to increase/decrease what nutrients. Just the way I was taught. That's why I ask for runoff. Might not make sense to anybody else, but works for me lol.
3rd Monkey
Well-Known Member
To be more specific to your question about non-ph affecting nutrients, if they are being used up, it creates an imbalance which is still detectable through ph and EC.
PH will tell you it's feeding more N if it gets more acidic due to the higher proportion of P, not necessarily the usage of N... And vice versa.
Also, your 3000 ppm would depend on the feeding of the plant and monitoring it's schedule. If there were excess nutrients or salt buildup, the plant would be telling you it's too much. Meters not needed.
Aussieaceae
Well-Known Member
Gday troutfarm,
Looks well overfed to me.
To a lesser extent, i think ph as well. As you have already pointed out, you had trouble with the ph a little while ago.
The damage almost looks like a severe calcium deficiency to me, which if the ph of the rootzone is too low, calcium will be less available. If you add too much nutrient on top of this it'll only make things worse.
If your water is in that 6.5 - 7.5 range, i wouldn't bother adjusting ph at all.
I'd also stick with plain water with plenty of runoff, for at least a couple weeks. Ride it out.
Best of luck, and hope they mend enough to see you through to harvest.
Looks well overfed to me.
To a lesser extent, i think ph as well. As you have already pointed out, you had trouble with the ph a little while ago.
The damage almost looks like a severe calcium deficiency to me, which if the ph of the rootzone is too low, calcium will be less available. If you add too much nutrient on top of this it'll only make things worse.
If your water is in that 6.5 - 7.5 range, i wouldn't bother adjusting ph at all.
I'd also stick with plain water with plenty of runoff, for at least a couple weeks. Ride it out.
Best of luck, and hope they mend enough to see you through to harvest.
This is not at all accurate, but if it works for you, it's all that matters!
Happy growing!
3rd Monkey
Well-Known Member
Well I'm game to get schooled up. This is how I was taught and I'm never done learning.This is not at all accurate, but if it works for you, it's all that matters!
It's served me well over the past almost decade. What's wrong with this?
Perhaps this paper will help? https://www.cropnutrition.com/fertilizers-and-soil-acidity
3rd Monkey
Well-Known Member
Thanks. I'll give it a read.
3rd Monkey
Well-Known Member
So... I'm not a botanist or chemist, I had to look a lot of shit up and retake 7th grade chemistry all over again, probably still only got it half right lol... But I think that says more or less the same thing I did just in fancy, harder to follow terms.
I did notice that potassium has no ph effect and that they included sulfur, which I didn't find necessary but as informative as I could take at the moment.
It won't let me upload the nitrogen picture, but it says basically what I'm saying.
My only issue with that article (other than what I already complained about lol), is that it disregards ppm... Which is the other very significant measurement.
If you could cite something very specific from that article and break it down to more lay mans terms, I could do my best to understand it.
The guy I learned from used this as a hydro method. I can't grow hydro due to my power being somewhat unstable in the woods, so I cross applied it to soil. Maybe that was my mistake?
I would like to know what it is exactly that is wrong with what I said though. It's worked well for quite some time, on cannabis and fruits and vegetables.
That said, if it's wrong, maybe it's not all wrong? As I definitely saw similarities between the article and what I am trying to convey and I have used it, so it does work. Just trying to figure it out.
Thanks, for the article and your time.
Aussieaceae
Well-Known Member
To be fair, i think we really can't definitively tell what's in our waste runoff without a proper analysis.
We may have 1.6ec of solution going in, which we can tell fairly accurately what the 1.6ec is, because of the lab analysis supplied with our nutrients.
But if having problems in a dtw hydro for instance, and our solution going in is 1.6ec but our waste is 3.6ec, then all we can really do is assume is it's too high. All we have is 3.6ec of ?????.
Also unless it's a small pot, i really do think reading the waste from soil is inaccurate at best. I think the only real thing we could analyse ourselves are trends.
If we started reading the waste from day one, it was fairly consistent with our 1.6ec going in and slowly crept up to 3.6ec. Plus our plant's health deteriorated while the waste was climbing, then we can make an assumption we're overfeeding.
But everything else really is a guess imo. Throwing in the ph of the waste makes it more of a guess. Because we can't know what exactly our plant is consuming, or what our medium is leaching.
It's all just a guess. Sometimes a very good guess, but a guess nonetheless.
We may have 1.6ec of solution going in, which we can tell fairly accurately what the 1.6ec is, because of the lab analysis supplied with our nutrients.
But if having problems in a dtw hydro for instance, and our solution going in is 1.6ec but our waste is 3.6ec, then all we can really do is assume is it's too high. All we have is 3.6ec of ?????.
Also unless it's a small pot, i really do think reading the waste from soil is inaccurate at best. I think the only real thing we could analyse ourselves are trends.
If we started reading the waste from day one, it was fairly consistent with our 1.6ec going in and slowly crept up to 3.6ec. Plus our plant's health deteriorated while the waste was climbing, then we can make an assumption we're overfeeding.
But everything else really is a guess imo. Throwing in the ph of the waste makes it more of a guess. Because we can't know what exactly our plant is consuming, or what our medium is leaching.
It's all just a guess. Sometimes a very good guess, but a guess nonetheless.
3rd Monkey
Well-Known Member
If I may take a crack at your example of a rising ppm. On a fresh flush, you fill with 1.6. After a duration, your EC is at 3.6... There are a couple factors at play. Hence the ph reading.To be fair, i think we really can't definitively tell what's in our waste runoff without a proper analysis.
We may have 1.6ec of solution going in, which we can tell fairly accurately what the 1.6ec is, because of the lab analysis supplied with our nutrients.
But if having problems in a dtw hydro for instance, and our solution going in is 1.6ec but our waste is 3.6ec, then all we can really do is assume is it's too high. All we have is 3.6ec of ?????.
Also unless it's a small pot, i really do think reading the waste from soil is inaccurate at best. I think the only real thing we could analyse ourselves are trends.
If we started reading the waste from day one, it was fairly consistent with our 1.6ec going in and slowly crept up to 3.6ec. Plus our plant's health deteriorated while the waste was climbing, then we can make an assumption we're overfeeding.
But everything else really is a guess imo. Throwing in the ph of the waste makes it more of a guess. Because we can't know what exactly our plant is consuming, or what our medium is leaching.
It's all just a guess. Sometimes a very good guess, but a guess nonetheless.
If you are using a higher ppm tap water, your overall ppm will rise. If your plant drinks more water than nutes from excessive temps, ppm will rise. If you add more nutes to the res, ppm will rise. If you have a salt buildup, ppm will rise. If you have a light leak/temp too high and algae is forming, ppm will rise.
Beyond that, there's not really a way for EC to rise. Your ph reading will start checking off options and lead you to the cure.
A plants health deteriorating is how you rule out that a stable 6.5ph with a 3000ppm is no good. It's just a balancing act.