Rising PH in hydroponics

Sick Plants & Problems
#1

Hi

i have flowers in plastic, UV resistant, buckets. They are clones in Jiffs hanging in plastic baskets slightly touching water surface. I have used Biobizz starter pack, mixed it with tap water and filled buckets with it.
PH was decreased by Citric Acid 3 days ago, but raised up to 7,2 again just one day after. Now i am stuck with approx 7,2 and i am not sure if i should continue to add Citric Acid.
Water in tanks also stinks, but i suppose you have to expect this when one of fertilizers is fish mix.

It is about week i have placed clones there and from the very beginning they have below symptoms:

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I believe its caused by deficiency of some nutrients necessary for healthy grow.

Can be caused by high ph? I decreased ph to 6,4 once, but another day it was back to 7,2 and i wont do it again for two reasons

  1. could it toxic to flowers? (i am using Biobizz´s product which states Citric Acid)
  2. it is time consuming and as there was not outcome before i don´t want to mindlessly try it again.

Can be caused by insufficient nutrients in the first place? Is there a way how to measure nutrients in my solution? Can this be done by EC meter?

I would like to ask you to advise me as i am new to this and there will be some mistakes in my doing.

Thank you!

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#2

The problem is you’re using fish emulsion in hydroponics. That’s not the right application for that fertilizer. There’s no way to reign in the pH when you use organics in a liquid reservoir like that. I recommend deciding whether you want to use fish emulsion or whether you want to use hydroponics, and then adjusting accordingly. Good luck to you! :thumbsup:

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#3

Also

I used Bio Grow, Root juice and Bio Heaven and i used approximately half of suggested amount, simply out of fear and believing that less cannot harm as much as too much.

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Now i wonder if i should add this amount of fertilizer every week or if it is OK. I would really like to have a way how to measure nutrients in it.

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#4

I found that my pH was drifting up. It’s because my starting water rises in pH for 3-4 days after coming out of the tap.

The solution for me was to let my water sit for 3 days allowing the pH to stabilize and then add nutes and pH as needed.

If your water isn’t stable, neither shall be your pH.

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#5

Thank you for your response. Is there any way how can i stabilize it. Or do i have to fill tall tanks again?

#6

So actually bottle says that it is made from plants, but they are organic anyway. I never knew that fertilizers has to be different for hydro. Sadly i was not advised about this in local growshop.

#7

I can’t tell but it appears that you are attempting Kratky style of hydro? This works well for some types of plants but is not optimal for cannabis, so it’s a bit of a challenge. You want to ensure that the nutrient solution is properly oxygenated otherwise

  1. the plant will have difficulty taking in nutrients
  2. the solution will harbor anerobic bacteria if the dissolved oxygen become deficient, the kind you do not want to have around. While plants will cause PH to increase, the organics, temperature, oxygen encouraging bacterial growth is a possible cause to the rapid PH increase.

As @hush notes, organics in the nutrient solution can lead to the growth of undesirable bacteria. Organics in hydro can be tricky to pull-off particularly if the solution is not oxygenated and the temperature is not managed.

Citric acid can be toxic to plants if you keep having to add it to the solution. I don’t know at what point that would be, though. A dilute sulfuric or phosphorus based acid may be a bit better.

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#8

Yes passive hydroponic. Roots should be able to breathe, so to speak, because they are not fully merged into solution. Also i use LED, so there should not be problem with temperature.

#9

Change the water, Add fresh nutes and dont Add the fish emulsion , in about a week or so they should be ok.

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#10

What is the ppm/ec at?

#11

If the Jiffs are touching the water, they will stay soaked. If the roots stay too wet, they cannot breath. The roots that are in the water will use up the oxygen in the buckets. In short - your not giving them nearly enough oxygen.

Also, you MUST keep the PH in range or the plants will not do well. Citric acid is a bad choice for hydro - its organic based and doesnt last.

As was mentioned before - you are using organic based nutrients, which don work well in hydro. I would change to Jacks or some other NON-organic nutes.

Not true at all. Do you know what the water temps are? You really need to measure it to know.

To sum up:

  1. Change to NON-organic based nutes. Its probably bacteria eating the organics that is causing the PH t go up so badly.
  2. Keep the PH in range at all times - use sulfuric acid or Phosphorus based acid. You may need to adjust very often.
  3. Check water temps. Try to keep it under 70 deg F.

Im not a fan of the kratky method at all. It has very poor oxygenation mainly and just begs to grow bad bacteria.

Good luck!

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#12

If you want a super simple method of hydro that does work well for our plants, try Hempy Buckets instead. They are the lowest maintenance type of hydro there is. All you do is water the buckets every few days and deal with the runoff.

Seriously, Id Google Hempy Bucket and see what you think.

You still need to switch away from anything organic in your nutes.

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#13

Yeah that’s not true at all, and @anon32470837 already touched on those points so I won’t repeat him. Temperature is always a concern when working around electronics that consume electricity. It’s physics. But more importantly you need to immediately rethink your setup. If you want to go with passive hydroponics, you should go to a top-feed style system, or you should do a hempy bucket. There is a reason why hempy buckets are so ubiquitous in this scene. They work, and they work extremely well. But if you are going to do hydroponics, you need to get rid of your organics. Those two worlds should NEVER be combined until you are highly advanced at both, and even then there is plenty of science that suggests it’s an uphill battle and just not worth the effort (outside of aquaponics, perhaps). So, lose the organics, buy a bag of Maxibloom or Jack’s, and stop reinventing the wheel. Do what is already proven to work.

The other option of course is to keep the organics, and ditch the idea of going hydroponic. I’m not a fan of that option for a multitude of reasons, but primarily because I believe organics are for the ground and hydroponics are for containers. I’m weird like that. Whatever you decide to do, it’s important that you decide. What you’ve setup for yourself is a high probability of failure, and I don’t like seeing that. I like seeing people succeed at this! That’s how we overgrow the world.

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#14

Here’s a pretty good video that may be of interest:

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#15

I agree with @Foreinger, stabilize your pH by letting the water stand 24-48 hours of you’re not using chemicals to remove the chlorine. Then add your nutes in the proper order.

You should pick up a tds/ec meter too. Some nutes I use have to be 1/2 strength (still takes me to 950ppm) 1/3 or 1/4 strength with little ones like you have there. But might not work with organics … hope you figure it out :blush:

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#16

I recently discovered that chlorine is acidic and it makes sense that ph would rise as it dissipates.

So obvious I missed it :slight_smile:

#17

The amount of chlorine we use to sterilize our rez water (2-4 PPM) doesnt change the PH to any significant degree. Ive run as hi as 20-50 PPM with no significant change in PH. Most drinking water that is treated is in the same range.

So, chlorine may be acidic at the concentrations inside a bleach bottle, but not in our grows. There isnt enough chlorine to cause a change for us to worry about one way or the other as far as PH. Now toxicity is a different story.

#18

That’s quite interesting. Maybe something else accounts for my rising pH

#19

I think most of its covered by others.

Air, tds meter, test for chlorine hard water to begin would all help. Everything in order to make sure nothing gets locked up.

Looked up biobizz. Sounds like you used a starter kit they sell, did it recommend the fish fertilizer they sell? And the pH down they have is citrus based. Did they sell this as hydro?

I think othes have recommended using a fertilizer specific to hydro to start.

#20

There are several things that can drive PH upwards. In no particular order:

  1. Biological action - algae, bacteria, etc can drive the PH up in a rez when they eat the nutes. This is especially a problem when using nutes with any organic components. Nutes like Jacks 321 dont have this problem (or its greatly reduced) because they have no organic components. Advanced Nutes, Mega Crop, Fox Farm all do have it.

  2. Alkalinity of the water - alkalinity in your water may drive the PH up all by itself when aerated. My water for example will always go up to around 6.3 when aerated. I add PH Down, then when its aerated, the PH goes back up. Add more PH down, it goes back up. Keep adding PH down, it keeps going back up. Never stops.

  3. Interaction with healthy roots can also drive the PH up - or down. This depends on your EC level mainly as far as I can tell.

Depending on your setup, this can be difficult to diagnose.