It’s not important to know. It’s nice to know. As long as the PH is within the buffering region, you’ve got it. You’d only need to know the concentration of the KOH if you are being analytical and/or using it to verify the buffer at the concentration intended is working as expected.
FWIW, I don’t really know if MES reacts with hypochloride in any way.
@5mM MES, the difference needed to move the PH should be quite noticeable. As in, 4x the amount of KOH needed within the buffering region to move the PH.
I don’t know. Are we talking about the EC of the solution already in the system or the EC before it was added? Was the solution cloudy at all prior to the addition of MES? Any precipitation in the system? What was the target EC of the fresh solution?
On the topic sanitizing, look up the Fenton reaction. Not for a live system but for cleaning before the next cycle. Eats organic material like Jeffery Dahmer.
Excellent analysis, and thanks for those pics. I have always found it very difficult tying to pin down a symptom. I always seem to have more than one thing going on. Most annoying is that many symptoms are the same for different deficiencies, and its even worse when they use the same pic for two different ones!!
As far as what to do to try to correct, I am not the person to ask. However, it occurs to me that I am using Potassium Hydroxide as PH UP and Phosphoric acid as PH down. I have not been using much if any of the Potassium Hydroxide, due to my PH always going up. I do use the Phosphoric acid a good bit, but maybe not enough?
I have no idea if those two will increase the available potassium or Phosphorus in the correct forms that would be useful to the plant, but I dont know what else to try either. When I re-fill later today I think I will add the MES first, then some Phosphoric acid to drop the PH even lower. That will require even more KOH than I used last time to get back up to 5.5, so the K should be better as well.
Im just shooting in the dark here, so any other ideas are very welcome.
Im disappointed in myself for not measuring the KOH when I made up the solution. I like being able to put numbers on things when doing this type of stuff.
I have not seen any mention in anything Ive read that adding the chlorine shock changes the chemistry in any way - good or bad, but that doesnt mean there couldnt be something going on. Chlorine is very reactive so it would not surprise me if it was messing with something.
4 times seems like its in the ball park at least. For sure, the MES is helping some. At 3AM the rez was still at 5.5 and the tank was at 5.6 and the nozzles were at 5.7 - which was a big improvement, but thats only a couple of hours after I finished re-filling the tank. By 1:30 today, the rez was still 5.5, the tank was 5.8 and the nozzles were at 6.0. Thats better than with no MES and has the nozzles at a much better PH, but its still a bad situation.
The EC in the rez started at 1.05 or so. It didnt look cloudy but the Advanced nutes have always had a slight film on top of the water - like a very light dusting of something. The Mega Crop never did that. Other times when the PH was hi in the rez, I did see signs of precipitation/clouding of the water, but not this time.
Alright!!! Thats exactly the kind of thing I was looking for. Obviously, strong chlorine just isnt killing all of this crap, or its managng ti hide in s=tiny crevices or something. I was planning to do at least a 24 hours soak in strong chlorine again - which I may still do, but I think I will start with this Fenton reaction.
The MES is helping a good bit. Its been almost exactly 48 hours since I added the MES and the PH in the tank and the nozzles is staying at 5.8 and 5.9 respectively while the rez is still at 5.5.
Ive been debating increasing the MES to see if the PH at the nozzles will stay any lower, but I think I will just leave it there for a few more days to see if it starts back up again.
Ive considered lowering the PH in the rez even more, but that starts pushing outside the buffer range of the MES, so I dont know how well that would work. Since the PH will almost immediately climb above 5.5 once its in the tank - maybe that would be ok?
I might try that first before adding any more MES.
I would. I measure PH at the point it gets fed to the roots and adjust the tank so the PH at the roots is right.
I would make the spray out of the nozzles the right PH if you can, that is all the plants care about at the end of the day. They have no knowledge of your troubles, the PH in the tank, or anything. All they know is what is on their roots.
If some process is raising your PH by 0.5PH between your tank and your nozzles then make your tank 0.5PH lower if you can without precipitation. How low do your nutes say they can go?
Maybe make a few jars with different PH values and see where it precipitates.
I’d try that first before adding additional MES. The three values seem to have more or less stabilized over that 48 hour period.
Don’t get confused on what buffer capacity means. The buffer chemistry itself doesn’t get “consumed”, you can move the PH in and out of the buffering region and the MES is still there and available for ion exchange (assuming nothing is precipitating or eating the MES itself). As long as a there are sufficient cations and anions, the buffering region should look the same even if the PH happens to be outside of the buffering region. It just won’t slow the changes to the PH as readily until the PH enters into the buffering region. Buffer capacity is the size of the chemical “sponge”. The chemical sponge is re-usable. A buffer is not intended for doing the actual PH adjustments (though MES free acid is an acid in this case).
For MC (version 1), during titrations, I didn’t note any immediate precipitation below PH7 or so (down to below 5). Even then, the precipitation that occurred at above PH7 appears mostly soluable when the PH was brought back down. Over a long time frame, however, there does seems to be some hard precipitation in the standard PH range (some sort of slow reaction) but I do not have the data to back that. FWIW, it was noted that citric acid may help counteract this if it does occur. It moves the precipitation to PH9 or so. The buffering thread has some preliminary notes on that.
Ok. Don’t know why the EC changed that much then. MES may have something of a chelating effect and it may increase the solubility of some minerals.
It seems like your tank is some sort of chinesium bioreactor. Which is kinda cool but maybe not in this case.
Quick up-date then I have to run again. The combination of extra chlorine shock and MES is working!
The MES alone was able to keep the nozzle PH at 5.9 while the rez was at 5.5. Lowering the PH in the rez to 5.3 dropped the nozzle PH to 5.7 and its stayed at 5.7 for the last 12 hours or so. Woo hoo!
Yeah, thats one of those things that when you finally think of it you go - DUH!! It never occurred to me that the PH would be different at the nozzles than it was in the tank. I ASSumed the PH would be the same all through the hi-pressure parts of the system, and I didnt add the tap to draw samples until just recently.
Ah, thanks for that. I was vaguely wondering about that consumption thing. Glad its not an issue. Of course, the MES gets used when the nutes get used, but thats not the same thing.
I was worried that even with the MES, the PH in the tank would keep rising, but hopefully slower than before, so this is working much better than I had thought it would.
I suspect some of the success is due to the increased chlorine PPM, but I think its mostly the MES. The PH is still going up, so that means the algae is not dead, but maybe the chlorine slowed it down some.
Im going to try dropping the rez PH down another point to 5.2 and see how that goes for another 12-24 hours, then Im going to start raising it up again.
Hopefully, between getting the PH down to a better point and adding extra phosphorus and potassium, the deficiency will at least stop progressing.
I checked more carefully when I topped off the rez and added more MES to the fresh water. Turns out the EC going up is due to me draining nutes back from the tank into the rez. What ever the reactions that are raising the PH, they are also increasing thr EC to some degree. Im going to have to start checking EC at the nozzles as well as PH.
LOL What ever it is I am going to kill it. That Fenton reaction looks like just the thing to kill it AND eat away what ever dead bodies are left over. Im a little worried about the rubber bladder in the tank, but its useless unless I can get this stuff totally out of the system, so Im going to do it anyway.
I checked trichs again, and more of them are milky, but very few amber. Well under 1% at a guess.
Here is an illustration on capacity and what it means as related to the buffer pka values:
The buffer should certainly slow it down. The relatively large and rapid jump in PH between the reservoir and the tank (and then to stay stable) is a bit odd. Only thing I can figure is that there was a remaining quantity of un-buffered solution in the system effectively diluting the buffered solution such that the buffer capacity was largely exceeded initially. Or, maybe it’s the shock that is interfering with how the PH is moving having killed the algae. In changing of several variables, it’s difficult to tell what’s doing what. Clearly, you have to do what you need to do, just a bit ummm, strange on the initial movement of the PH.
Yeah, I wish I could get away with changing only a single variable at a time, but the plant is in too bad a shape and its obvious that the algae is/was coming back strongly in the pressurized parts of the system, but I don think I have time to wait.
The way this is going down has me puzzled too. I am glad its working this way, but Im having a hard time seeing what the mechanism is.
Its a complex situation with a lot of unknown variables.
This started with 100% Advanced nutes at EC 1.0
Initially, I completely drained the tank back into the rez before adding the MES and adjusting PH. Then I pumped some of that into the tank and then back to the rez. The idea was to have the entire system - low and hi pressure - starting out with the same exact mix with the MES and all starting at the same PH = 5.5.
Within about two hours, the rez = 5.5, the tank was 5.6 and nozzles at 5.7.
Twelve hours later it was Rez= 5.5 Tank=5.8 Nozzles = 6.0
At that point, it was time to re-fill the rez, but Im about out of ADvanced nutes and I really dont like the stuff floating ont he surface or the apparent precipitation swirling in the water, so I left 3 gallons of that in the rez, and added about 8 gallons of RO and Mega Crop to get back to EC 1.0. I added more MES at 5mM again, and did the PH down, followed by more PH up to increase the amount of phosphorus and potassium in the solution - per @MicroDoser analysis of my deficiencies.
Ive also been adding chlorine every top off for several days - increasing up to about 6PPM.
Over the last several days, the PH difference between the rez, tank, and nozzles has been slowly decreasing.
Dropping the rez PH to 5.2 this last time dropped the PH in the tank AND the nozzles down to 5.5! This is the first time the tank and nozzles have been the same sense my last super heavy chlorine treatment.
I can only assume that the steady doses of chlorine have been slowly reducing the amount of algae in the hi pressure parts of the system. That part I can understand.
What seems odd to me is that in between top off or re-fill, when Im making NO changes to the rez or any other pert of the system, the difference in PH between the rez, tank. and nozzles remains constant. In other words, if the rez was at 5.4 and the tank was at 5.6 and the nozzles at 5.7, they stayed at those exact levels until I changed the PH in the rez. I fully expected the PH to slowly climb in the tank and at the nozzles, but it has not.
It seems to much to expect that I was killing off algae at the exact rate necessary to keep the PH from rising, but I cant think of any thing else.
Twelve hours ago, I dropped the rez to 5.2. When I checked again 6 hours later, the nozzles were at 5.6. Then by 10 AM the nozzles were at 5,5. I decided that was long enough and time to raise the PH back up, so I increased the rez PH to 5.4 from 5.2. A few hours later the tank AND the nozzles are at 5.5 while the rez is still at 5.4.
The algae must be getting killed off - finally - by the steady chlorine.
So, I just now drained the tank again, and raised the rez PH from 5.4 to 5.5. I will check again in an hour or so and see what the tank and nozzles are doing. Im going to need to top off the rez again in another day or two, and Id like to swing the PH up some first.
I will be topping off with straight Mega Crop V2 again, but Im going to lower the MES to 2mM from 5mM. With the signs of the algae being less active, I want to see how the lower concentration does.
Im done with AN nutes.
Almost forgot - there was a film that looked like fine dust on the surface of the water with the AN nutes for the last many days. Plus some signs of precipitaion in the mix. After adding the Mega Crop on the re-fill, that all went away.
It seems that if you do chlorine often enough - Ive been dosing almost every day - at hi enough doses - 4 to 6PPM - it will knock this algae back pretty good! I guess before, when I was doing the “sterile rez” thing, I wasnt doing it often enough or strong enough or both. Previously, I was only doing around 2-4 PPM every 3 or 4 days.
The last 12 hours or so, the PH at the nozzles has been exactly the same as the rez. The previous 18 hours or so, its only been up 0.1 at most. So, Im counting that as a knock down for at least a two count, but probably not a knock out.
Im very glad about that, but it has cost me fuzzies. I cant find any fuzzy hairs anywhere I can reach or see. Im going to pretend there are still some hiding in places I cant reach - which is maybe 80% of the chamber at this point.
The roots actually look pretty good - just not fuzzy.
I re-filled the rez with 6 gallons of RO, Mega Crop and MES at 2mM, and additional chlorine at 2PPM this time. There was still about 3 gallons in the system of the old mix at 5mM of MES, so the final concentration should be somewhere in the middle. Im too stoned to be sure Im doing the math correctly, so Im not going to give a number
We will see how this does.
Other than the cost, Im impressed with how well the MES has handled the upward PH pressure from the algae.
Sorry, Im slowed down with kidney stones again. No big changes, but a new mystery.n I hope this makes sense - Im pretty stoned and in pain…
Reducing the MES and stopping chlorine additions every day, allowed the PH to increase in the tank and nozzles again. It went up to a 0.2 - 0.3 difference. Still, that was better than with no MES for sure.
Increasing the MES back to the 5mM range improved it - the PH rise dropped to 0.1 in the tank and another 0.1 at the nozzles.It seemed like the lack of added chlorine was keeping the MES from working as well as before. In other words, it appeared that the MES and the chlorine were each responsible for roughly half the PH rise.
BUT - then today, the rez has gone up from 5.7 to 5.9 over the last 24 hours, and for no reason I can figure out, the rez, tank and nozzles are all at the same PH = 5.9. I have NOT added any chlorine or MES, so Im stumped. Ive been feeling so bad the system has been running on LITFA.
The plant continues to look about the same. Some more foxtails have shown up over the least week or so. The oldest fan leaves on the lower parts of the plant look a little burned on the edges, but not bad. The middle aged leaves mostly look horrible - brown, burned and crispy. The youngest leaves look half decent, but there isnt much in the way of new growth. The roots continue to look like nice healthy hydro roots, but with almost no fuzzies to speak of. It does seem like they have finally stopped or at least slowed growth a lot.
Trich’s still look mostly milky with very few amber, so I still have a ways to go before harvest. Today is 58 days of 12/12. The range for this strain is 50-60 days, so it looks like Im going to run long rather than finish early.
I am expecting a good harvest as far as weight though. The main colas are significantly bigger than on my earlier grows. I have not seen any hermies or bannanas yet, but I would not be surprised if there were some after all this PH and other stress. Oddly to me, the top most buds pistils are still mostly white, but the lower ones and shorter colas are turning brown much sooner. There is an interesting purple tink showing on some of the buds. No clue if thats due to the PH issues or strain related.
I went to my grow shop the other day and had one of the usual ‘cryptic but ultimately very informative and spot on once I get a chance to think about it’ conversations with the owner.
We started talking about the plant, the symptoms, what I had done to try and find the cause of the leaf issue we both have. He was able to tell me the exact cross I have, and the name of the person who made it, and why, the year it was made, and the characteristics of my plant just because I told him it was psychosis and said the symptoms. Turns out I grow the psychosis cross made by Exodus (original psychosis was not made by them) which was destined for outdoors, very resistant to mould, grows strong, finishes early, and will continue to repair root damage well into flower and ensure a good yield in times of problems. He was even able to tell me that in normal times, the stalks of the leaves have a red tinge.
He does lectures at universities on plant science and is involved with international food production programs and is a consultant for a new plasma light in development.
He knows stuff…
I have yet to fully process what he said, and as usual, I need to google for a bit to figure it out properly.
Seems the P def we appear to have might be a lockout due to interaction with the CalMag or other additives (I now need to google what can cause P lockout). Either that or because of the highly tuned nature of our systems we need MUCH fewer nutrients in the solution and we are overloading the ionic transport system at the root surface and as it has preferences for other elements this manifests as a deficiency. Like the way alcoholics get a B12 deficiency he said.
And of course, it could still be a PH issue.
He did confirm signs that is indeed a P def are red leaf stalks and the red moves toward the main stalk, also in very early stages it shows as a slight leaf bend where a leaf looks like it will grow to the left then half way through looks as though it will grow to the right.
Anyway, I have things I can do to test deeper the cause and solution.
I will be keeping PPM levels well under 650, they just stopped eating at 700PPM. I will be in the 5.35-5.55 range at the nozzle more. I will be using a lot less CalMag now I know it is not a Ca or Mg def.
Once I have at a minimum reduced greatly the outward issues and they are growing well again, I will up the nute strength and play more with the PH.
@SuperiorBuds Im looking forward to hearing more of your thoughts on what you posted. I have some comments on nute concentrations, but that will have to wait.
Very interesting. It sure does seem like we are having similar issues - and as usual, there is no clear cut cause/effect or guaranteed solution! Thats the price we pay for playing with systems that have highly complex interactions with a great many unknown variables I guess
On the over strength nutes point, I thnik your NFT setup is probably subject to the same or at least similar issues we have with HPA - evaporation causing the nute strength to increase dramatically at the roots over what it is in the rez.
Here is how it can work with HPA. Take say a 1 cc volume of nutes that start at EC 1.0. If that 1cc is in a cube shape, it has a surface area of 8 sq cm. for evaporation to occur. However, if you break that same 1 cc of nutes into 50 micron droplets, you get 8 million of them. The total surface area is now 1600 sq cm. instead of 8 sq cm. So, the water in those droplets will evaporate 200 times faster when its broken up into tiny droplets.
If one of those droplets has time to evaporate enough to shrink in diameter from 50 uM to 25uM, the volume will decrease by a factor of 8 (Volume varies as the cube of the radius). That means the EC will go from 1.0 to 8.0 just due to the water evaporating from the droplet. Even small amounts of evaporation can make for large increases in EC between the time the droplet leaves the nozzle and the time it hits a root and gets absorbed.
I noticed early on that around EC 0.8 to 1.0 was about as high as I could go without tip burn.
This evaporation thing is also a factor in the Membrane Meniscus system I tried. Being able to use lower concentrations of nutes was one of the selling features. The whole point of that system is to provide the absolute minimum thickness of water to the roots as possible. In function, its like an NFT setup, but with the thinnest possible film of water on the roots at all times. Surface tension is all that causes the water to coat the roots rather than a fast flow or stream over the roots. That super thin film will also be subject to faster evaporation, though not to the extent spherical droplets are.
I suspect that any NFT system will also have some degree of additional evaporation going compared to other types of hydro. Mostly because of the far larger surface area of water exposed in the pipes and as it flows over the roots. It would be more pronounced where roots are more exposed to air and have thinner layers of water.
Anyway, the point is it makes sense to me that you might need lower EC levels than other types of hydro. How much lower I have no idea. Might not be significant or it could be a lot.
You might be able to check and see if there is any difference between the EC when the nutes leave your rez, before it hits the plants, and what it is right before it drains back to the rez? I suspect it will depend on your flow rate as well. Hi flow rates will probably eliminate any differences.
Ive been adding a ton of extra calmag to my system as well, so maybe I will cut back on that as long as I have the PH more or less under control now.
Its probably coincidental, but my burned leaf issues started when I switched to the Advanced Nutes. I mixed up the first batch at the recommended strength 0 which gave me an EC in the 1.6 range. I didnt lower it back down nearly fast enough. Of course, that was also the height of the algae/PH issues, so who knows how much of a factor that really was.
If you have any more thoughts on the leaf issues and the P def, Im all ears
Almost forgot - the PH in the rez, tank, and nozzles are all still the same despite the much lower chlorine levels.
It seems to me that the more frequent addition of chlorine, at lower doses, is working much better than waiting 3 to 4 days between adding some at higher doses. I know it evaporates out of the system pretty quickly, but I didnt expect it to be that fast.
Im concerned that it may be building up in the tank because there is no where for it to evaporate to, but I have no good way to measure free or total chlorine. I have some strips but they suck. They dont read anything below about 20 PPM or more.
Im going to have to look for a better testing method.
I think this is our winner, I was also doing this. It is the main thing I have cut down in the last few days. I was trying to chase what I thought was an Mg def by adding more Mg/CalMag and keeping the PH in a higher range.
It seems this may have been the exact opposite of what I needed to do. Last time I was there I really went to town with extra Ca and Mg with the idea that if this did not stop the deficiency, then it was 100% not a Ca or Mg def. It did not help, so it is 100% not Ca or Mg.
When I visited them and saw it had not helped, I emptied the old doser buckets of nutes and remixed some with hardly any Ca or Mg, refreshed the tank, and lowered the PPM to 350 and the PH to 5.4 and now they have started eating again.
Now (as I am in the last 2-3 weeks of flower anyway) I will slowly ramp up the feed, being careful to stay in the strength where they are still eating, and keep the PH low as I am sure they are full of lots of the stuff they can get at a higher PH…
I have been growing in this system for well over a decade, I feel certain that if there were issues with water evaporation causing nute strength increases I would have noticed by now, this moves my thoughts more towards the more recent changes which are RO, and too much CalMag.
The RO may have thrown out my base numbers, my tap water is at about 380PPM and PH 8.4. Getting rid of all that and keeping the same numbers would mean an overfeeding of up to 300PPM. I did drop my feed strength but maybe by not enough.
Here is the change in the last two weeks. The first image is bang on the crossover between weeks 4 and 5 (2019-2-5). In this image, you can see the slight leaf twist that is an early sign of a P def according to my shop guy.
Here is another shot to see the leaf damage. There are leaves as damaged as yours lower down, but I took these shots to check bud development and growth.
It sure looks like our leaf issues are very similar, although mine seems much worse than yours. Oddly, my older, lower leaves are much less damaged than the middle and upper leaves.
Now that Im not quite as stoned, I want to ask more about the comments that it could be the CalMag causing the problems. Did your guy happen to say what type of calmag was problematic or if it made a difference?
Your guy sounds like he is an honest to goodness real expert rather than the usual ‘stoner experts’ we often run into, but this is the first time Ive read anything about calmag causing issues like this. Have you found any other sources to back this up?
Im asking mainly because of one thing that occurred to me last night. I didnt see anything like this degree of problem until I switched brands of CalMag. I was using the GH CalMag which is the Calcium Nitrate and Magnesium Nitrate. The new one I have been using since this issue started, is Calcium Hydroxide and Magnesium Carbonate - no nitrates in either one.
Aside from the lack of nitrates, Im wondering if the added hydroxide or carbonates could be an issue? There are two differences btween this calmag and the GH calmag. The GH calmag increased EC, but didnt seem to change PH. The new CalMag is just the opposite - it lowers PH but doesnt change EC much at all. Obviously, the chemistry is very different.
Changing to the new non-nitrate calmag, plus switching to Advanced Nutes at higher concentrations were the two major changes I made at the time the leaf damage started to show up. Of course, the PH was wildly out of bounds on the hi side, so Im sure that was also a factor.
As usual - complex systems and changes with little concrete facts to go on.
No. Like I say, he is rather cryptic and encourages me to find out things for myself but puts me on the right path. He knows his onions and I have had enough experience with him to know I do not need to double check what he says, although please feel free yourself as you do not have my years of being impressed by the subtle and cryptic guidance.
I don’t think a particular brand matters. He was talking about alcoholics and the way that even though they are taking in enough calories, they have thin arms from malnutrition. He particularly said about them having a B12 deficiency because the body prefers to uptake alcohol over B12.
In that context, asking the brand of alcohol or type of product with B12 does not matter, it is something that will happen no matter the brands.
He then went on to say that the CalMag products, and particularly the mono-element products I was buying are very very strong, even though the percentage number on the bottle might not be a very large number and this was a place to look.
As I say, I have now removed 90% of the Ca and Mg from my system (they are probably chock full of those elements now), I am now just giving them part A and part B (and some silicon) at a lower strength and they have started eating again at the rate I would expect for this stage in flower. Since the other day I have increased the food from 300-400PPM. 2 days ago they did not want to eat at 350PPM, now they are eating at 400PPM so good signs.
There are places I would investigate for more knowledge, like which particular elements can interfere with P uptake at the root surface and so on but for a solution, he seemed pretty product agnostic and it seemed the advice was mostly to just put less in.
To really know what is going on, and which changes are the ones responsible for the negative effects they need to be looked at in isolation. This is not really possible in a live system that is not set up like a scientific experiment.
So we must be like Dr House and treat for something and use that as a diagnostic tool with the logic that if the treatment works, we have found the problem.
I have treated for an Mg def and this made things worse. I will be going back to basics, lowering strengths, just putting in A+B, silicon, and maybe a bit of root stim/boost with minimal CalMag (I will probably go back to CalMag over mono bottles now I am sure this is the wrong area of investigation)
I will be starting at a level of CalMag where I should expect a deficiency over excess and I will only increase the CalMag if they show certain signs of Ca of Mg def.
I have tried a few, the mixed ones made my plants go dark green from the nitrogen but I think that was because I was putting too much in. I have not found a mixed CalMag without N in it so I went to the mono bottles with zero N in and my plants have still gone dark green from having the PH too high chasing a non-existant Mg def…
All this leads me back in a big circle to just putting less in and keeping my PH lower.
