Help! Think it's nute burn but I'm way under dosing.

[chewmills]

Hey guys,

Hope someone can help. I'm growing a Barney's LSD auto in a hydro system and using Coco nutes. I know my room can get hot so I've dialled down the nutes to half the recommended light feeding schedule.

Can anyone help me with what's going on in these pics before it gets worse? I've already got a fresh watrt flush going.

 

[Rwise]

I dont do hydro, but they will need more input from you. The first thing I would want to see is the PH range, but give up some details so they can help.

 

[oldjarhead100]

I agree with Rwise we need more details off the top of my head I would say they are heat stressed 30 C = 86 f so 30.3 is a couple of degrees higher now in a well ventilated room with input air and exhaust air with fans blowing on the plant that might not be a problem or if your running c02 but dont worry they will recover and flourish .the details we would like are ph.ec.water temp in res how are your roots are they white or light brown .and the nutrients you are using

 

[oldjarhead100]

Lights your using and distance from the plant and if your room is like mine the high and low temp over 24 hours

 

[dphipps1020]

Just curious how do your roots look? That's a pretty high temperature for hydro growing. I had around the same temperature for a while and I kept getting root rot so I had to change a few things. What is your pH? You want it usually between 5.8-6.2, at least that's what worked well for me. Do you know your ppm or EC level? I didn't really pay attention to that but it helps to know and the more experienced can help better if they know. Are you adding anything for the roots? Something similar to Hydroguard maybe? I've never used Coco nutrients so I can't really add anything useful about that.

 

[YYCannabis]

Hydro guy here.

Your VPD (ratio of temp:Humidity) is way way off the charts. You need to get the humidity up to around 65-70% for those temps, or get the temps way way down for that humidity. What you’re seeing is partly due to dehydration. The plant is working hard to stay moist (drinking water) but isn’t taking up nutes because you are at low dosage. (Even at full dosing, your plant is more thirsty than hungry)

To be able to help further, we need more info:
1) Lights (wattage and height above canopy) and schedule
2) Nute levels (ppm or EC)
3) pH level of reservoir
4) Are you adding CalMag and something to prevent root rot?
5) Temp of the hydro reservoir
6) Feed schedule (when do you do fresh change? Do you do plain water top-ups in between changes?) and what brand of nutes are you using?

Below is 2 images that you should keep on hand.

In hydro, there are 3 things that you must check every day:
1) water level (How much water is she drinking in 24 hrs)
2) pH levels (rising or dropping compared to prior day)
3) ppm/EC levels ( How much is she eating in 24 hrs)

 

[SoOrbudgal]

I think this was a issue chewmills had before? Is this a old post reposted?

 

[YYCannabis]

Time stamp is from this morning.

 

[chewmills]

Hydro guy here.

Your VPD (ratio of temp:Humidity) is way way off the charts. You need to get the humidity up to around 65-70% for those temps, or get the temps way way down for that humidity. What you’re seeing is partly due to dehydration. The plant is working hard to stay moist (drinking water) but isn’t taking up nutes because you are at low dosage. (Even at full dosing, your plant is more thirsty than hungry)

To be able to help further, we need more info:
1) Lights (wattage and height above canopy) and schedule
2) Nute levels (ppm or EC)
3) pH level of reservoir
4) Are you adding CalMag and something to prevent root rot?
5) Temp of the hydro reservoir
6) Feed schedule (when do you do fresh change? Do you do plain water top-ups in between changes?) and what brand of nutes are you using?

Below is 2 images that you should keep on hand.

In hydro, there are 3 things that you must check every day:
1) water level (How much water is she drinking in 24 hrs)
2) pH levels (rising or dropping compared to prior day)
3) ppm/EC levels ( How much is she eating in 24 hrs)

Thanks a lot and sorry for the delay. I've been absolutely floored with tonsillitis but flushed with fresh water and the new growth is looking OK so it's still salvageable.

I'll take as many of the measurements/readinds as poss and get back to you. I'm going to get the temp down first but getting more fans and an extraction fan in there tonight.

This isn't a repost but I did have the same issue before.

 

[chewmills]

Thanks a lot and sorry for the delay. I've been absolutely floored with tonsillitis but flushed with fresh water and the new growth is looking OK so it's still salvageable.

I'll take as many of the measurements/readinds as poss and get back to you. I'm going to get the temp down first but getting more fans and an extraction fan in there tonight.

This isn't a repost but I did have the same issue before.

1) Lights (wattage and height above canopy) and schedule

KINGBO 900W full spectrum. Leave it on 24 hours. It is 25 inches from the top of the canopy; I cannot get it any further away than this.

2) Nute levels (ppm or EC)

EC = 1.1

3) pH level of reservoir

pH = 5.5

4) Are you adding CalMag and something to prevent root rot?

Canna Rhizotonic

5) Temp of the hydro reservoir

23 degrees Celsius

6) Feed schedule (when do you do fresh change? Do you do plain water top-ups in between changes?) and what brand of nutes are you using?

I change once a week. Yes, I do plain water top ups in between changes. I am using Coco Canna nutes.

I have managed to get the grow tent temperature down to 23 degrees Celcius and the humidity to around 35%.

 

[chewmills]

I agree with Rwise we need more details off the top of my head I would say they are heat stressed 30 C = 86 f so 30.3 is a couple of degrees higher now in a well ventilated room with input air and exhaust air with fans blowing on the plant that might not be a problem or if your running c02 but dont worry they will recover and flourish .the details we would like are ph.ec.water temp in res how are your roots are they white or light brown .and the nutrients you are using

Hey, thanks for helping. I have updated the info in my post above this one.

 

[YYCannabis]

Ok...
Your lights being on 24hr could be stressing the plant’s root. Roots do their growing during the night; the leaves grow during the day...while cannabis plants *can* be kept under 24hr lights, i don’t believe it’s the best way to grow.

Your EC is ok.

PH is your issue. The pH MUST travel up and down the range of 5.5-6.5 in hydro grows. If you have been keeping it down at 5.5, you need to get it up to around 6.2-6.5 for the next week or two.

You plant is starving for more calcium, which is why most hydro growers add Cal/mag additives to the nutes. I can’t say anything about using Rhizotonic, but from a quick google it seems that’s an additive for root production and not root PROTECTION. You need something that prevents root rot.If you want to stay with the Canna brand of products, you need to buy Cannazym
https://www.canna.ca/cannazym

23C for the reservoir is too warm and is prime temp for growing nasty bacteria in there. Search the GWE website for tips on how to cool it down.


Good schedule for feed. Are you checking the EC/pH/water level every day?

You temp is much better. If you can get humidity up to 50% your plant will be thankful.

SO after all that blabbering....your problem is most likely root rot. You need to deal with that ASAP.

 

[chewmills]

Brilliant, thanks. I'll up the pH and put a damp, white towel over my resevoir. That should reflect heat and help get the humidity up. I've got a fan blowing at the top of the resevoir so I'll check the temp in the morn.

I already use cannazym but I do have Calmag, too.

Thanks again for your help!