DWC Problems - Nutrient Deficiency?

[GrumpAzz]

So what VPD should I aim for? I’m just kind of going by what I read online and I’ve found a few sites that say keeping VPD between .8-1.2 is best for veg.

So I just try to keep it in the middle of that range. But if you think I should be doing something different, by all means please let me know. Ty!

Yeah. A VPD of 1 can grow a decent plant. Ideally you'd wanna up that going into flower.

Remember VPD charts are referring to leaf temps with their temperature recommendations. That can be anywhere from 2-6 degrees cooler than your environment.

I run 80 degrees at 70% until it really starts to show some growth. Once it seems like she's wanting to run, I'll drop the humidity to 60-65% and bump up my temp to 82ish, depending on leaf temps. Ideally, you'll want your leaves between 75-80 degrees. Going into flower, I'll run 82 degrees at 50-60% humidity.

And btw, I’ve changed res and reduced nutes to about 20% of my original dosage. Since then she’s seemed to stabilize a bit and perk up. The deficiency markings are still there but she does seem healthier.

Even though when you’re just starting off and trying to dial shit in, and you get a problem you can’t figure out at first and start to panic…the whole problem solving part of this is so fun and fascinating. Just based on how this first grow is going I can say I’ll be doing this for the rest of my life

Thanks for all your input and advice. You guys rock.

Those leaves won't improve either. They'll show that damage until they die off or they're removed. No big deal, really.

You've got a great perspective and sound a lot like me when I started out. I've been lucky to cruise through my first two harvests with little to no deficiencies (knock on wood). You'll get in a groove and it'll all start to fall in place. The water chemistry is the most difficult part of hydro, obviously. Get a grasp on that and it's mostly smooth sailing. Just wait til you smoke your first nug... oh what a feeling.

 

[moe.red]

Even though when you’re just starting off and trying to dial shit in, and you get a problem you can’t figure out at first and start to panic…the whole problem solving part of this is so fun and fascinating. Just based on how this first grow is going I can say I’ll be doing this for the rest of my life

Growing cannabis feeds your brain. Twice.

 

[Observer]

So what VPD should I aim for? I’m just kind of going by what I read online and I’ve found a few sites that say keeping VPD between .8-1.2 is best for veg.

So I just try to keep it in the middle of that range. But if you think I should be doing something different, by all means please let me know. Ty!

I try to keep my tents at 85f/75rh all of veg and all of flower, till last week or two, but I'm trying to push my plants and optimize all the variables as much as i can/control.

Leaf surface temps need to be at least 77f for optimal growth rate/photosynthesis under LEDs.

 

[Observer]

Yeah. A VPD of 1 can grow a decent plant. Ideally you'd wanna up that going into flower.

Remember VPD charts are referring to leaf temps with their temperature recommendations. That can be anywhere from 2-6 degrees cooler than your environment.

I run 80 degrees at 70% until it really starts to show some growth. Once it seems like she's wanting to run, I'll drop the humidity to 60-65% and bump up my temp to 82ish, depending on leaf temps. Ideally, you'll want your leaves between 75-80 degrees. Going into flower, I'll run 82 degrees at 50-60% humidity.


Those leaves won't improve either. They'll show that damage until they die off or they're removed. No big deal, really.

You've got a great perspective and sound a lot like me when I started out. I've been lucky to cruise through my first two harvests with little to no deficiencies (knock on wood). You'll get in a groove and it'll all start to fall in place. The water chemistry is the most difficult part of hydro, obviously. Get a grasp on that and it's mostly smooth sailing. Just wait til you smoke your first nug... oh what a feeling.

Most of those older vpd charts are room and rh, unless I'm mistaken.

VPD Chart | AROYA

VPD Chart

vpd.aroya.io

This link here is a vpd calculator that you can slide
Air RH
Air Temp AND
Leaf surface temp

These IR guns are cheap at Wally world to measure the leafs

 

[Aqua Man]

I haven’t read replies but you have far to much light right now no matter what because the plant isn’t healthy you need to dial it down as low as you can.

Cut that cal mag down to 1/4 dose.

You N is probably high because if it. As seen by the shiny leaves.

Trim off the bottom 2 leaves and get just a gentle breeze over the too of the bucket so it carries the humidity away.

RH at about 55-60%

400ppm is fone but i think your ratios are out so like i say cut cal mag

What does the surface of the water look like from the air? Is it violent?

It won’t drink much its tiny so thats normal.

Biggest thing right not is cut that light way back until this is sorted

 

[Aqua Man]

Oh and tour oh is way too high. What are you using to buffer it? Right now it ahould be around 5.5-5.8 that may be part of your nutrient problem

 

[Aqua Man]

Grrr PH may be part of your nutrient issues

 

[Aqua Man]

As was said air temp is to cold. Under led you want to be anywhere from 75-85 depending on leaf temps… an educated guess for you would be about 79-81f for ideal leaf and plant temps.

In my experience ideal water temps are around 70-74 with 72 being ideal. Run bennies though. I recommend defgaurd.

 

[Observer]

aqua to save the day

 

[Aqua Man]

aqua to save the day

Nah just smashing some geriatric fingers on a phone. I didn’t read all the comments as im in the middle of some work. Almost this old mans bed time

 

[moe.red]

I think we lost @SkinnieP

Skinny if you have not met aqua he is a legend in these here parts. I would 100% listen to anything he says.

He’s the one that taught me RDWC. But don’t hold that against him some of his students actually do pretty well.

 

[GoodShit97]

I think we lost @SkinnieP

Skinny if you have not met aqua he is a legend in these here parts. I would 100% listen to anything he says.

He’s the one that taught me RDWC. But don’t hold that against him some of his students actually do pretty well.

Agree.
@Aqua Man is the Man! I mean cmon, it's part of his handle for a reason

 

[SkinnieP]

I haven’t read replies but you have far to much light right now no matter what because the plant isn’t healthy you need to dial it down as low as you can.

Cut that cal mag down to 1/4 dose.

You N is probably high because if it. As seen by the shiny leaves.

Trim off the bottom 2 leaves and get just a gentle breeze over the too of the bucket so it carries the humidity away.

RH at about 55-60%

400ppm is fone but i think your ratios are out so like i say cut cal mag

What does the surface of the water look like from the air? Is it violent?

It won’t drink much its tiny so thats normal.

Biggest thing right not is cut that light way back until this is sorted

Hey man, sorry for the delay it's been a wild week. Luckily I read your reply and implemented your recommendations.
So I dialed the light back 50%, trimmed the lower leaves and switched the nutrients to a granular floraflex just to see what would happen.
Since then she's happy asf and starting to grow quite a bit.

The surface of the water... I wouldn't say it's violent, but it's got quite a lot of bubbles from the airstones. I put two airstones in there and there's some definite improvement on the bubbles. How much is too much with bubbles?

So for the temperature, yeah I want to push higher temps but the issue I'm having is the water temp. It's only a single DWC system so I'm not sure I want to drop $200 on a cheap 1/10 water chiller... only because this IS my first grow and I'm growing hydro dwc & soil side by side just to find out what I like most. So if i push the temperatures to 75-80F that would pretty much put my water temps out of the ideal range, right? That's what's holding me back.

I tried bennies in my other DWC system (RIP OG Kush) and she got root rot(i think) and I just tossed her.
With this one I've been dosing with 2ml of H2o2 about once every 2-3 days.

 

[Aqua Man]

Hey man, sorry for the delay it's been a wild week. Luckily I read your reply and implemented your recommendations.
So I dialed the light back 50%, trimmed the lower leaves and switched the nutrients to a granular floraflex just to see what would happen.
Since then she's happy asf and starting to grow quite a bit.

The surface of the water... I wouldn't say it's violent, but it's got quite a lot of bubbles from the airstones. I put two airstones in there and there's some definite improvement on the bubbles. How much is too much with bubbles?

So for the temperature, yeah I want to push higher temps but the issue I'm having is the water temp. It's only a single DWC system so I'm not sure I want to drop $200 on a cheap 1/10 water chiller... only because this IS my first grow and I'm growing hydro dwc & soil side by side just to find out what I like most. So if i push the temperatures to 75-80F that would pretty much put my water temps out of the ideal range, right? That's what's holding me back.

I tried bennies in my other DWC system (RIP OG Kush) and she got root rot(i think) and I just tossed her.
With this one I've been dosing with 2ml of H2o2 about once every 2-3 days.

Ok that dose of h202 is good.

Water temps are more important that air temp and they influence plant temperature much more. The plant temps will always be higher that the water temperature. Set your environment to achieve 70-72f water temperature and call it good.

It always better to have to little light than too much. If you post pics every few days we can keep up on the progress. but they also will grow into the light so probably not much adjustment will need to be made.

You really don’t need a lot of light until flower when your reduced to 12hr of light only. Thats when you need the intensity.

Look up DLI (daily light integral) to understand the concept of this.

Bit do not go by number they give. Those are only for dialed in professional grows.

If you want an easier grow lower light will do that because it IS the driver of demands on all things

 

[Aqua Man]

Holy shit… thats got to be one of my most cryptic uses of English i have done yet.

Then again maybe not lol. These fat fingers strike again

 

[Aqua Man]

Also adjust your PH to 5.5-5.6 and then wait 24 hrs and let me know what its at. Ideally you want 0.1-0.2 rise no more than that in 24 hrs. Plants like stability…. Actually need stability. If its more we will discuss how to buffer your water to get you in that sweet spot

 

[SkinnieP]

Also adjust your PH to 5.5-5.6 and then wait 24 hrs and let me know what its at. Ideally you want 0.1-0.2 rise no more than that in 24 hrs. Plants like stability…. Actually need stability. If its more we will discuss how to buffer your water to get you in that sweet spot

So can I ask what your reason is for wanting PH in that range?
I think what was happening was a cal-mag deficiency caused by my RO water being too soft / combined with the PH swings.

I've had my PH set to 6.0, added a little epsom salt to the RO water first before mixing nutes, and putting in a little extra cal-mag. Since then she's exploded and looks very healthy. The PH swings haven't been a problem since adding the epsom salts, not sure why. But now it might go up .1 within 24-36 hours.

I'm working on a time lapse video for you guys, should be pretty cool.
Appreciate your help !!!

 

[Aqua Man]

So can I ask what your reason is for wanting PH in that range?
I think what was happening was a cal-mag deficiency caused by my RO water being too soft / combined with the PH swings.

I've had my PH set to 6.0, added a little epsom salt to the RO water first before mixing nutes, and putting in a little extra cal-mag. Since then she's exploded and looks very healthy. The PH swings haven't been a problem since adding the epsom salts, not sure why. But now it might go up .1 within 24-36 hours.

I'm working on a time lapse video for you guys, should be pretty cool.
Appreciate your help !!!

Nutrient availability for the stage of growth. The stability reason is like hot, cold, hot cold on a plant it causes stress and thats always going to cause a slight issue depending on how much stress.

Let me link a thread on PH that i did

 

[Aqua Man]

Thread 'PH Levels for Cannabis Explained by Aqua Man'
https://budbuilders.org/threads/ph-levels-for-cannabis-explained-by-aqua-man.196/

 

[Aqua Man]

You are likely over doing the cal and mag.

The epsom won’t change the PH much and does not contain a buffer. Potassium bicarbonate, potassium silicate are good options when combined with sulphuric or phosphoric acid to create a buffer.

If you want to work in this i can help you. Its easy and very important to learn in hydro

 

[Aqua Man]

Young plants and vegetative stage like a lower Ph 5.5-5.8 until around time to flower then generally 5.8-6.1 i always found nutrient issues when going over 6.2 in hydro although it very much depends on the nutrient ratios used