Ph Dropping From 5.8 To 3.9 Overnight! What Is Causing This?

[Kapazo]

You sound credible.

The comments I've quoted are of note to me.

What are your theories as to the issues Im having?

Should I just chalk up the pH fluctuations to "business as usual" and immediately flush the reservoir as some have suggested? If that was the case, wouldnt EVERYONE have these pH drops?

Should I pull a sample the next time it drops to get the nutrient solution tested? Would that give me a better indication of what was actually happening?

Im all ears.

Hi RFT, I came to the thread of this post looking for possible solutions to the problem that, from what I am reading, not only I am trying to solve.
I hope you know how to understand my English, I don't know English enough to express my ideas, so I did a translation of my Spanish and I will surely have several mistakes, but thanks to the technology that shortens these distances.
Coming to the point, I commented that I developed a recirculating deep water system, osmosis water and with an external zoom, just as I treat the water in my coral aquarium, just like FamilyCanna, whose appreciation made me see the problem from another angle. In this zoom is where I perform the measurements, cooling / heating, reduction of pH AUTOMATIC (phosphoric acid) addition of nutrients MANUAL, oxygenation. etc.
It was not difficult to identify with his problem since my plants develop under all normal parameters until week 4-5 where the PH collapses regardless of what I do. I already rule out pests, bacteria, cleaning, I am discarding the EC since regardless of its value the chemical process of acidification of the nutrient solution continues, and although the plants are healthy, but I see they lose their potential.
A striking bread crumb is the automatic ph dispenser, and I only name the ph since the nutrients I am adding from the beginning of the last harvest, manually, about what I wanted to ask,
1 How much does the pH reduce each dosage that the system asks for? (for example, in a ph of 6.2 the dosing pump is activated and the ph drops to 5.8),
2 How concentrated is the acid that dumped the system?
3 what type of acid do you use to lower the pH during the first weeks?
4 Does the ph down directly dump the hydroponic system? ,
Seeing the problem with the position of our colleague FamilyCanna and its detail about the consequences that we do not take into account in the treatment of water, a detail that is more prominent, since our main task in hydroponics is to take care of the optimal state of the water and the solution Nutritious guarantees perfect harvest.
Between his system and mine, I found that the two systems are recirculating and the treatment of ph is automatic, and the symptoms are exactly the same ... so, maybe we should focus on the dosage that the ph down performs during the previous weeks, if you are going through the same thing as me and you tried everything, we will share the intuition that there is a chemical process that we cannot understand, and that perhaps the way in which in a recirculating system the dosage of the ph is administered directly in the system is the cause of this subsequent imbalance, since I saw another case in another forum (https://www.invalid.com/t/ph-dropping-quickly-cant-get-away-from-4-6.1002149/post-15208718 the description of his problem is similar in post # 5 comments that ph system is automatic) and shares the characteristics of a recirculating system and automated ph and I see that this constant is the only one that is repeated despite our different systems, and I do not think it works Not all of our dispensers are bad, I think the dosing pumps do their job but the way they do it causes an imbalance in recirculating hydroponics .
Well, here I share my ideas and thoughts, I don't know if my intuition is correct, but I hope that we can understand and solve it at once.
Greetings from Argentina and have an excellent day.

 

[Kapazo]

I share a way without chemicals that I use at this time to regulate the PH in hydroponics when it tends to fall, as is the case of this post, using split coral stone (as you read it in my aquarium the calcium reactor I have to regulate the ph between 6.2 and 6.5 to acidify the solution) where these split coral stones decompose from the minerals they absorbed in life, in this decomposition alkaline form releases calcium and other components, the same that was used in my aquarium for reactors calcium, so in any marine aquarium store they have available
I separate around 250 gm in net bags and put them inside the zoom in an area of high circulation, this causes the elevation of the ph and does not alter the EC, I currently use 300 gr in 80 liters with a ph that tends to steadily drops, stabilize it in ph 6 without additives. I know it's not the solution, but it's a practical patch;)
I hope we find the solution.
If I am committing some outrage that someone tells me, I only have basic knowledge :)
Cheers

 

[Indiva710]

Well drip clean just prevents salt build up in lines and UC roots is a sterilizer, neither effect ph or EC. So its really only a 4 part nutrient feed. Been using this feed schedule for years and never had a problem.

My main concern is if this could be some kind of pathogen caused by bad filters or water source itself. But the roots look healthy so im just confused

I switched to pool shock instead of uc roots and so far so good and I'm 2mo into veg I run veg at 400-500ppm and never had a issue by doing so and the ladies are perfect too not a single issue or def..I also use vinegar for salt build up and does better than anything else it does lower your pH tho however it is not as stable as pH down is or critic acid but also depends on your nute program u use...Also depends on how long you been running those nutes in your system...I only drain my system if there's a issue but if the water is clear and pH stable I keep it as is and pretty much only drain at the end of a run for the most part..I been using cultured solutions and they have done wonders for my plants and I don't add anything extra etc...I also do not use calmag bs either as very rare will ur plant need both and cal nit is dirt cheap and mgso4 is even cheaper yet and problem solved...When I run out of c.s I'm switching to dry nutes for everything I pretty much already do like pH down using pool shock and cal nit and mgso4 and hydrobuddy is great to use if you do dry nutes

 

[Override]

Hey,

Joining in here as this problem is exactly the issue I have faced since switching to RDWC and this thread seems to have the best discussion and diagnosis I've seen on the problem.

Vegging goes fine then a week or so into flower the PH dropping begins and gets worse and worse throughout flower to the point where it can plummet from 5.8 to 4 in a matter of a few hours. I have done same diagnosis as others have cutting back to A + B alone, trying different EC levels, different temps, CO2 on, CO2 off, I have multiple PH pens and constant monitors so it isnt that, different strains make no difference. I have never got to the bottom of it.

My system is sterile with daily h202 so definitely no rot. Plants always look really healthy other than suffering later in flower due to me but being able to manually manage the PH drops.

I am an experienced grower with years under my belt managing different growing methods and do things very scientifically and methodically.

I use tap water which is very soft 0.1 EC which made me think that may be part of the problem although I have spoken to other hydro growers in the local area as well as local nutrient manufacturers who all weren't really familiar with this problem and could only say what many other suggest that it is root rot. This obviously made me suspect the issue must be to do with things unique to my system.

The most obvious unique thing I can think of is I grow very large plants in comparison to the volume of water in my res or at least I think I do. As a result turn over of water in my res can be as much as a third a day. It feels like this is likely a factor in my problem. The issue however never appears in veg so clearly the chemistry taking place during flowering is also a factor. During veg N is taken up to a higher degree which has the effect of increasing PH and in flower the uptake of P and K results in a fall in PH.

It seems like the natural Fall in PH created by the plants up-taking p and k in flower in combination with large plants turning over a lot of my nutrient solution on a daily basis causes this issue to become more apparent to me than people with smaller plants in similar sized systems. This is however my best guess based on the diagnosis I have done so far. I am very interested to hear other peoples opinions on this and also get feedback from others with the same problem as well as those who don't to what % of their water is used daily.

 

[RFT]

Hey,

Joining in here as this problem is exactly the issue I have faced since switching to RDWC and this thread seems to have the best discussion and diagnosis I've seen on the problem.

Vegging goes fine then a week or so into flower the PH dropping begins and gets worse and worse throughout flower to the point where it can plummet from 5.8 to 4 in a matter of a few hours. I have done same diagnosis as others have cutting back to A + B alone, trying different EC levels, different temps, CO2 on, CO2 off, I have multiple PH pens and constant monitors so it isnt that, different strains make no difference. I have never got to the bottom of it.

My system is sterile with daily h202 so definitely no rot. Plants always look really healthy other than suffering later in flower due to me but being able to manually manage the PH drops.

I am an experienced grower with years under my belt managing different growing methods and do things very scientifically and methodically.

I use tap water which is very soft 0.1 EC which made me think that may be part of the problem although I have spoken to other hydro growers in the local area as well as local nutrient manufacturers who all weren't really familiar with this problem and could only say what many other suggest that it is root rot. This obviously made me suspect the issue must be to do with things unique to my system.

The most obvious unique thing I can think of is I grow very large plants in comparison to the volume of water in my res or at least I think I do. As a result turn over of water in my res can be as much as a third a day. It feels like this is likely a factor in my problem. The issue however never appears in veg so clearly the chemistry taking place during flowering is also a factor. During veg N is taken up to a higher degree which has the effect of increasing PH and in flower the uptake of P and K results in a fall in PH.

It seems like the natural Fall in PH created by the plants up-taking p and k in flower in combination with large plants turning over a lot of my nutrient solution on a daily basis causes this issue to become more apparent to me than people with smaller plants in similar sized systems. This is however my best guess based on the diagnosis I have done so far. I am very interested to hear other peoples opinions on this and also get feedback from others with the same problem as well as those who don't to what % of their water is used daily.

You’ve tried A&B alone for an entire run?

What nutrient line?

 

[Override]

Yes have had this issue when using only A+B for a whole run with a few nutrient lines
Canna Aqua
Canna Hydro (Soft water specific)
Dutch pro Hydro
Plant magic hydro (soft water specific)
Plant magic DWC

 

[RFT]

Yes have had this issue when using only A+B for a while run with a few nutrient lines
Canna Aqua
Canna Hydro (Soft water specific)
Dutch pro Hydro
Plant magic hydro (soft water specific)
Plant magic DWC

After speaking to techs with prominent hydro companies I can tell you the following facts:

1. When they test these nutrients they do so in drain-to-waste systems. If there are problems with recirculating system compatibility, the mfg has no idea until the consumer finds out for them

2. Supplements are bandaids for system inefficiencies. Soil medium type growing is not as efficient as hydroponics. And thus why these supplements were created. If you’re doing true hydro, very little supplementation should be necessary

3. Some of the supplements (notably PK boosters) were never tested in recirculating systems prior to market launch and tend to end up having negative reactions to the nitrates in the solution after a few hours or days of circulating. Symptoms include diving pH, nutrition lockout, and nitrogen fallout

You need to find a nutrition product line that was specifically designed & tested for recirculating systems. Which isn’t always easy to find. Many, even synthetic nutes, were designed for soil type medium or drain-to-waste hydro. The nutrient companies are catering to what will sell the most products AND what the consumer is generally asking for. Most growers are of the drain-to-waste or timed feeding system type.

24 hr recirculating, is a more advanced system type and only applies to a fraction of the consumer base. Heck, some nutrient lines will even try to tell you that 24 hr recirculating systems are not higher performance than d2w. There’s merits to both theories I suppose. But considering I actually test both, and have no fiscal interest in either other than what actually performs better (not what uses the most amount of nutes) I think I’ll trust my conflict-of-interest-free judgement. That said, hydro is hydro and we’re splitting hairs as to what is actually the highest performing system type.

But it’s not splitting hairs when getting a nutrient program that matches your system type. As I have learned the hard (expensive) way.

 

[Override]

Very true. Canna aqua however is supposedly formulated specifically for re circulating systems.

Thing is I can imagine it's hard to make a bottled nutrient for re circulating systems because at the end of the day plants in different systems with different water use totally different amounts of various different nutrients all the time. When re circulating this means under certain conditions your nutrient mix can quickly become at best sub optimal and and at worst toxic. When the plants are using a high percentage of your mixture on a daily basis that process of imbalance is going to be much quicker. So all the manufacturers can do is try and formulate a mix that Hope's to keep the nutrient mix within acceptable balance for as long as possible but that isnt going to work for all situations. Really when you consider this drain to waste is always going to be superior to re circulating

Unfortunately I think in my circumstances that means i have to change out my tanks almost every day in peak of flower. I can only realistically adjust back up from PH 4 once with chemicals before the PH up further worsens the imbalance.

 

[RFT]

Very true. Canna aqua however is supposedly formulated specifically for re circulating systems.

Thing is I can imagine it's hard to make a bottled nutrient for re circulating systems because at the end of the day plants in different systems with different water use totally different amounts of various different nutrients all the time. When re circulating this means under certain conditions your nutrient mix can quickly become at best sub optimal and and at worst toxic. When the plants are using a high percentage of your mixture on a daily basis that process of imbalance is going to be much quicker. So all the manufacturers can do is try and formulate a mix that Hope's to keep the nutrient mix within acceptable balance for as long as possible but that isnt going to work for all situations. Really when you consider this drain to waste is always going to be superior to re circulating

Unfortunately I think in my circumstances that means i have to change out my tanks almost every day in peak of flower. I can only realistically adjust back up from PH 4 once with chemicals before the PH up further worsens the imbalance.

Solid points. For that reason I can see why d2w has merits, among others. Fresh nutes are fresh nutes.

That’s why with recirculating systems I feel automated dosing is mandatory to keep things in check. And then using a nutrition line that is formulated for cannabis, so that the imbalances wont occur. And then reservoir size must be larger than you think is necessary, so fresh nutes are always available.

But you gotta solve the pH diving issue first & foremost. There is something wrong.

 

[Override]

Yes I would love to solve it but im stuck :). I know for sure the problem comes about at least party due to what the plant is doing during the flowering cycle though as the problem only ever appears in flower regardless of how long I veg and increases in severity from the start of week 2 until around week 5 where it remains at its worse until the end.

 

[Indiva710]

Have you tried potassium silicate pure dry like agsil 16h as it raises your pH and it will Also keep it more stable so maybe something like that will work I read you ph to 6.0 to 6.5 which you could put it at 5.6-6.3 and see how that is..I only add ph down when it's at the upper number maybe a point or 2 away and I'll go back to 5.6 or 5.4 even and my top off res I run at like 5.2 or so just also depends on what the plants are doing and how much they are drinking...But a top off reservoir is a must have for rdwc not only do u keep a constant water level which is huge for the plants and keeping them happy....But also having fresh nutes in it does wonders too which I refill my top off 1x a week and add fresh nutes as my res for veg is 13gal only however it's plenty for veg and will last a week and that's the most I want it too same goes for the bloom setup ESP with bloom having it to drain in a week is huge as when I refill it for the next week I add the next week nutes so as they feed they get that weeks nutes and it does wonders too...

 

[Indiva710]

I use cultured solutions for my nutes right now however I will be switching or trying out dry nutes just cuz it's cheaper and kinda easier too in a way as when you have a specific deficiency u just need to add more for that one thing not a 1part bottle of everything and makes it worse or w e.. however I do like c.s alot actually like I've had zero issues with it and have used it for x4 grows now and the plants are always healthy and green and all I add is their veg and b And if they need more calcium I add cal nit and if they def on mag I add mgso4 and then sterilizer aka pool shock and h2o2 from time to time and I do citric acid for ph down and vinegar about 1x a week to help keep salt build up on parts...Which the vinegar does wonders for salt build up period hydro or Coco doesn't matter still works the same but lowers pH...The vinegar isn't as stable as citric acid is so it doesn't last very long for pH down as in having to do it daily but I don't use it daily and I use it to clean and soak air stones in as well

 

[RFT]

I will aso add that the nutrient companies not only run their tests in d2w, but they only use RO water

So nothing is accounted for with variables such as tap, spring, or well water

This creates a ton of variables they cannot account for. They simply assume, as a general baseline, that the nutes will work generically. Which is a safe bet, but not always the case

For example, most liquid silica brands only are designed to work with RO water. And in my case, had serious reactions to the existing small amounts of iron/cal/mag in my well water.

No label on the bottle will tell you this. Because it’s impossible that they could test for these variables prior to product launch

But be skeptical of any nutrient line that claims it works in all mediums or system types. That isn’t accurate. It works in what it was designed for & tested with. I know of synthetic nutrient lines that were predominantly designed for soil w/ spring water and tested in only that environmental w/ limited hydro testing. Yet their label says they work for all mediums. “Work” is a very loosely used word in these cases.

 

[Indiva710]

Agreed water source has a lot to play in it too I use r/o for that specific reason as it's always the same for the most part and tap water also depends on what pipes are opened at that time your getting your water since diff water stations use different things..Like my tap will be 50-120ppm now that's not bad but I have no clue what's in it and depends wat station is pumping water at that time so it's a pure guessing game which is y I've been using r/o and it makes things easier don't have to compensate for only god knows what's all in it...

 

[Roadblock]

Maybe the water temps in channels are fluctuating to much or too quickly with gives the plant micro stresses that lower metabolism causing PH drop, a plant thats in a cold snap will go into shock but what if its only minor they may have a random PH shift .

I see those channels would have no insulative effect, in soil the root zone would have no sharp shifts in temp, Ive seen a PH drop over night that was because of a cold snap, I quicky got it back in the zone and the PH stabilized. Using Aqua Flakes nothing else in a RDWC.

Hope you find the cause.

 

[DreamwalkerJ]

Hey im not sure this will help you but have you checked for algae? A tiny bit of light leaked into one of my buckets during one cycle and caused some algae to grow. The tiniest amount of algae made it back to the res and into my venturi pump filter, so pumping water through algae made the pH crash. Cleaned the pump filter, lowered water level by 1 inch and covered the buckets. Problem solved. I dont know if this helps anyone but hopefully it will. Happy growing, friends