Help a friend with dificiency

Troubleshooting
1

My buddy sent this pic and it looks like there’s a dificiency. Red leaves but also spotting on leaves.

He’s using miracle grow and I already know that’s partly to blame; however, I’m hoping to get some advice on any remedies he may have.

Obviously flushing is out. He’s using tap water ph 7.2 Obviously he needs to bring the pH down but if I could get some feedback on what specifically his symptoms look like I can try and communicate that to him. as many times as I’ve told him to get a pH meter he’s not taking my advice, but if I could get some feedback from someone more knowledgeable than I am, maybe I kid Communicate that to him, and he could see the peril of his ways.

Thanks so much

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2

The biggest deficiency he has is light intensity. Cannabis is an extremely light hungry plant and needs multiple hours of direct sun reach day to be productive.

A few plants in MG will do fine. Most won’t. Let’s get more information if we can and we’ll go from there. Runoff pH and PPM are needed. I expect the runoff pH, if not being monitored and managed, is very low because of the MG. This will starve the plant of most forms of nutrients except iron, manganese, and boron. NPK, cal, and mag are likely to be locked out if runoff pH is below ~5.5, which is very possible with MG. MG has time release nitrogen that submarines your pH every time you water, so the high pH of the water going in is a good thing, not a bad thing.

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A support ticket will help us help you. Can you please fill out a support ticket? Please include what type of water you are using (RO, distilled, tap.)

COPY/PASTE the below list into your forum post.

Answer these simple questions the best you can.

If you do not know, or do not use something; Just say so; Or post

NA (non-applicable)

• What strain, Seed bank, or bag seed

• Method: Soil w/salt, Organic soil, Hydroponics, Aquaponics, KNF

Soil brand and type

• Vessels: Pots, Grow beds, Buckets, Troths

• Runoff pH

• Runoff PPM/TDS or EC

• Indoor or Outdoor

• Light system and wattage

• Temps; Day, Night

• Humidity; Day, Night

• Ventilation system; Yes, No, Size

• AC, Humidifier, De-humidifier,

• Co2; Yes, No

If growing Hydro some additional questions:

-DWC? RDWC? Autopots? Ebb and Flow? Other?
-Distance of liquid below net pot (DWC)
-Temperature of reservoir
-TDS of nutrient solution
-Amount of air to solution

Always try to upload a clear picture of any issues you may have to allow the community to assist you. Pictures taken under natural or white lighting are by far the best.

Add anything else you feel would help us give you a most informed answer should be included. Feel free to elaborate, but short and to the point questions and facts will help us to help you in a more efficient manner.

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3

Hope this helps

4

This is extremely high. Are we sure this is accurate?

Can’t help much without understanding the root zone (runoff) pH. pH from a soil slurry test would be fine too.

I expect pH is one of the main issues if in MG.

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5

Ya. I gave him a tds meter and his tap water reading was the same as what I’m getting with my meter so he went home and got some runoff and it was 5000 one time and then 5200 another.

Will work on getting ph run off soon.

6

Something is wrong with the PPM meter. No municipality is going to allow this to happen to their tap water system. What brand is it and when was the last time it was calibrated?

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Oh, I’m sorry for the misunderstanding. Yes I believe the reading of 5000 was accurate because his TDS meter and my TDS meter both read our tapwater at 450 ppm. So when he went home and tested his runoff with his TDS meter and it read 5000 I believe it was an accurate reading.

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8

We may be able to help a little by doing what we can with pH so the plant can eat, but the plant is flowering and has matured in a deficient environment. There’s not a whole lot we can do to make significant improvements at this point.

The plant can probably make it to the end, but it isn’t going to be very productive.

The 2 best suggestions I have for future grows are more light and a soil that is properly pH buffered for cannabis. Fox Farm products, Coast of Maine, Roots Organic, and Black Magic are all good cannabis soils.

It’s probably not a good idea to try to transplant it at this point.

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9

The following chart shows plant nutrient uptake potential as it relates to soil pH. Perhaps this will help convince your friend how important pH monitoring and management is.

The pH scale is logarithmic, meaning that the a pH of 5.5 is 10x as acidic as a pH of 6.5. Whether or not a plant can eat is dependent on whether or not the pH is in the ideal range of 6.3 to 6.8. pH is extremely important for this reason.

Soil pH
Soil pH441×503 42.4 KB

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Awesome I really appreciate it.

If we use a ph meter to test runoff is that appropriate? Because that’s how I usually test runoff. I haven’t done a slurry test before.

With mg, should we raise water ph going in until water coming out is 6.3-.6.8? My understanding is if ph is low, water going in should be no higher than 7 as to not cause other issues and over time ph will come up. With mg, from what you’re describing, is that it’s going to constantly be pulled down by nutrient beads. Would it be ok to put water in at 8 or higher to bring it up?

Just trying to understand options

Thank you

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11

Most accurate way to check ph is to do a slurry test.

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12

If you are in flower your ideal ph is between 6.5 and 6.8 in soil. BUT soil temp plays a role also. Ideal soil temp is around 78°F. The colder your temps , the colder your soil, the slower the uptake. If your ph is 6.0, then you would want to ph in water at 7.2… but what i do is not water till runoff. I slowly water till i get a tiny bit out of the bottom and let it sit. As the ph comes up, it slowly releases the nutrients and the plant will start uptake. Im guessing the the ph is tanked and the ppms have skyrocketed

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Some recommend against it, but I’ve done it multiple times without issues. I wouldn’t go any higher than 8 though. It can take time to get it fully adjusted up.

That would be the goal. It may be a challenge. The best way to correct pH is to flush, but that isn’t really possible when in MG. Those nute pellets can be a PITA.

Correct. Every time the plant is watered it releases more nitrogen and acidifies the soil a little more each time.

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