Reoccurring problems every grow WOODY J (UK) to the rescue

[fartoblue]

It may finally be getting through to me! The next few weeks will tell!

Every grow I am experiencing Calcium deficiency at around week 3-4 into flower and duly a less than optimum harvest. The cal deficiency escalates so I up my PH to over 6 and add more cal although I am sure they have enough (DWC by the way).
The leaves shrivel nearest the lights so I think maybe nute burn so drop my feed to 1.1 after a res change, nothing much changes and my grow turns out substandard.

My mate who is more experienced says I am feeding far to low, he feeds at well over 2.0 all be it in flood and drain and beats me hands down every grow even though he doesn't seem to care about things as much as I do, (green fingered ba$t&rd).

I have read some of Woody J's old threads on a UK forum (I believe he also posted on here) and hopefully it is finally sinking in.

I can see he makes sense but it goes against everything else I have read. " Static water level, Nute ec going up means you are feeding to high as the plants can't take any more nutrients so don't drink, reduce ec and plants will drink more then work your way up from there.

Woody's advice below

Most people assume that with a rising EC, it is the plants way of saying, I don't want more food, here, have some back.

What is actually happening is this.

Plants roots take in water/nutrients through a process called Osmosis. Effectively, if you think in terms of the roots having their own internal EC.
The osmosis process will always try to balance out the EC's, taking from the higher side of the barrier and giving to the lower part.

So if the EC of the nutrient solution is higher than the "internal EC", then food & water will flow from the solution to the roots, this is the normal process.
"If however, the EC of the solution is lower than the "internal EC", then the balancing will work the other way and nutrition will be leeched from the roots to the solution. "
A res change or increase in EC should resolve depending on the other factors such as ph and water levels.

So I am now thinking as calcium is semi mobile and I am feeding to low it is leeching from my roots and plants into the nutrient solution.

I will reword this sentence above "So I am now thinking as calcium is semi mobile and I am feeding to low it is leeching from my roots and plants into the nutrient solution"

I don't think it will be pulled from the plant as it is not truly mobile and cannot be trans-located I think maybe it cannot be up taken due to the plants equalizing their environment. Do I have this correct ?????

My problem has always been static ec and constant dropping PH (I have seen Woody's chart) with water/nutrient levels all over the place sometimes drinking then suddenly slowing for no reason.

Maybe I am feeding them at basic maintenance and as soon as full flower kicks in they are struggling.

I've been growing for nearly 3 years now all be it in 4 different systems but have only managed over gram watt on a few occasions. Am I missing something ??

 

[JohnDee]

farto,
First thing...you can't really compare a DWC to an Ebb and Flow. One's roots-in and ones roots out. Sounds like your buddy is a better grower then you...and his would outperform you if the systems were reversed. It's like chess. A better player will always win over one less advanced. No shame in it...just the facts.

Point being...leave your buddy's grow out of the discussion. Matters not.

You have res temps to consider. Do you know how they've been?

And how do you know you've been having Ca def? Brown spots? Your statement that you added more Ca even though you knew they had enough...that troubles me.

Why add it then?

My thinking is that you're having some sort of nute interaction...or maybe bad room conditions

Ca is carried upward into plant through the movement of fluids...so proper transiration is crucial. Too much light or heat and transpiration slows. Not warm enough and transpiration slows. With LEDS you need to bump the temp to open stoma because no infrared in LEDS...or transpiration slows. Get my drift?

What water are you using? RO?
I'm gonna stop for now.
JD

 

[myke]

Im in the same,Spots as I get deeper into flower.I have tried upping nutes and like you ph takes a dive.My spots start at mid plant and go up from there.Only thing that I can think of is my light,600hps is too much.I run it at 24" above now.My room is also cold,65~75.
I currently have a small 4 pail dwc going to try and figure it out.one has high nutes others are lower.

 

[Merlin1147]

I will reword this sentence above "So I am now thinking as calcium is semi mobile and I am feeding to low it is leeching from my roots and plants into the nutrient solution"

I don't think it will be pulled from the plant as it is not truly mobile and cannot be trans-located I think maybe it cannot be up taken due to the plants equalizing their environment.
Do I have this correct ?????
No. it doesn’t work this way. Water is pulled into the plant through transpiration like a straw. This bring nutrients to the roots. Once at the root they are actively transported across the casparian layer into root cell individually. once inside they stay inside.

 

[JohnDee]

No. it doesn’t work this way. Water is pulled into the plant through transpiration like a straw. This bring nutrients to the roots. Once at the root they are actively transported across the casparian layer into root cell individually. once inside they stay inside.

I think we're talking two different things...both part of the process of getting Ca to the plant. Yes...there is diffusion across a gradient...from high concentration to low.. That is at the cell wall membrane. But the whole thing can be halted without transpiration.
JD

 

[Merlin1147]

I think we're talking two different things...both part of the process of getting Ca to the plant. Yes...there is diffusion across a gradient...from high concentration to low.. That is at the cell wall membrane. But the whole thing can be halted without transpiration.
JD

Roger that JD. I was just addressing the one statement. Transpiration is the key to it all.

 

[myke]

I added a fan to blow directly on my said plant to help with transpiration,no response.Rh 45%

 

[myke]

Hope its ok to jump into your thread @fartoblue very interested to find a solution.cheers.

 

[fartoblue]

farto,
First thing...you can't really compare a DWC to an Ebb and Flow. One's roots-in and ones roots out. Sounds like your buddy is a better grower then you...and his would outperform you if the systems were reversed. It's like chess. A better player will always win over one less advanced. No shame in it...just the facts.

Point being...leave your buddy's grow out of the discussion. Matters not.

You have res temps to consider. Do you know how they've been?

And how do you know you've been having Ca def? Brown spots? Your statement that you added more Ca even though you knew they had enough...that troubles me.

Why add it then?

My thinking is that you're having some sort of nute interaction...or maybe bad room conditions

Ca is carried upward into plant through the movement of fluids...so proper transiration is crucial. Too much light or heat and transpiration slows. Not warm enough and transpiration slows. With LEDS you need to bump the temp to open stoma because no infrared in LEDS...or transpiration slows. Get my drift?

What water are you using? RO?
I'm gonna stop for now.
JD

Many thanks for your reply JD
3 x 600w HPS @ aprox 18" from bulb to plant tops, whilst the plants nearest to the lights are the worst affected leaves on the edges of the canopy 3ft away are still having the same problems.
These plants are 6 weeks and 5 days from flip, the very first signs of this started at around 4 weeks the same as it always does. I have another room on a different system and it has just started showing the same symptoms. they are different strains and some (Sherbalato) are affected worse than others some also have Taco leaves but this may be due to hot spots under the Adjusta-wing hoods.

I feed GH 3 part ratio more or less all 3 equal until finish of stretch then adjust 3B 2M 1G followed by 3B 2M 0G then 2B 1M 0G. I was running 123 321 but changed with just the same results. Only other additives are Botanicare cal/mag @ just over 1/2 strength and Canna Boost (recent addition) 2ml per litre. My background tap water ec is 0.2. Feeding at around 1.0 ec first week in flower raising to 1.2ec, these numbers are inclusive of my background ec so maybe I should be knocking this off. PH corrected to around 6 every morning dropping as low as 5.5 before corrected.

This is how it starts


Then this


Then this all crinkled and dead, dry as old sticks

Curling leaves on plants less affected


Room temps lights on

Lights off all be it my other room but it is the same.

 

[fartoblue]

Some more pics
Res temps a bit low but I don't think it would do this.


Roots, This is a secondary root system as they are top fed into 20 litre rock wool croutons 3-4 times daily in a recirculating system which is changed every 10 - 12 days.

 

[fartoblue]

Hope its ok to jump into your thread @fartoblue very interested to find a solution.cheers.

Course not mate more the merrier.

 

[fartoblue]

I will reword this sentence above "So I am now thinking as calcium is semi mobile and I am feeding to low it is leeching from my roots and plants into the nutrient solution"

I don't think it will be pulled from the plant as it is not truly mobile and cannot be trans-located I think maybe it cannot be up taken due to the plants equalizing their environment.
Do I have this correct ?????
No. it doesn’t work this way. Water is pulled into the plant through transpiration like a straw. This bring nutrients to the roots. Once at the root they are actively transported across the casparian layer into root cell individually. once inside they stay inside.

Thanks for this Merlin. I read this (below) on another site an this is what made me think about the equalization thing.

Another concept, osmosis, is the net movement of water driven by solute concentrations across a membrane that is semi-permeable and selective. If the solute concentration is higher on one side of the membrane, water will move to create an equilibrium between intracellular (inside a cell) and extracellular (outside the cell) solute concentrations. This movement of water creates a pressure either inward or outward. For example, think of a balloon filled with solute (NaCl). Next, imagine that balloon is surrounded by pure water. Since the concentration of salt inside the balloon is high, water will move into the balloon and place pressure that will inflate the balloon. Without outward rectification, the balloon would pop; thus, salts must be transferred out to reduce this water (osmotic) pressure.

 

[myke]

Course not mate more the merrier.

One thing that has helped me is foiler calmag @1ml/l,in veg.Cant spray in flower.Some other things Ive tried as you have probably tried ,extra air stone,upped Mg to 100ppm ,fan on the uderside and lastly added 2ml/l calmag.I think Ive slowed it down but not much.

 

[JohnDee]

I feed GH 3 part ratio more or less all 3 equal until finish of stretch then adjust 3B 2M 1G followed by 3B 2M 0G then 2B 1M 0G. I was running 123 321 but changed with just the same results. Only other additives are Botanicare cal/mag @ just over 1/2 strength and Canna Boost (recent addition) 2ml per litre. My background tap water ec is 0.2. Feeding at around 1.0 ec first week in flower raising to 1.2ec, these numbers are inclusive of my background ec so maybe I should be knocking this off. PH corrected to around 6 every morning dropping as low as 5.5 before corrected.

Farto,
I can't help but feel this is related to toxic salt buildup. Testing runoff should clarify things. If that number is high...you'll need to flush. Are you getting regular runoff. Rockwool, just like coco, needs 20% minimum runoff. This should be the obvious first thought any time you have symptoms of multiple deficiencies.
JD

 

[fartoblue]

Farto,
I can't help but feel this is related to toxic salt buildup. Testing runoff should clarify things. If that number is high...you'll need to flush. Are you getting regular runoff. Rockwool, just like coco, needs 20% minimum runoff. This should be the obvious first thought any time you have symptoms of multiple deficiencies.
JD

Many thanks for looking in JD. I water 3 times each day for 15-30 minutes so I can rule salt build up out. whatever is in my res will be the same as what is in the medium.

I pushed the ec up to 1.4 which is higher than I have ever fed. It is a last resort so we shall see. Maybe should have listened to my smart arsed mate.

 

[fartoblue]

Here is another gem from Woody J taken from a UK forum.

I think it can be very confusing what to do when you have what appears to be nutrient burn, the automatic response is to lower the EC. However, generally, this just makes things worse.

The key to understanding what is happening is the water levels as I mentioned. If they are more or less static when into flower, something is wrong. The issue then becomes what to do about it?
Increase or decrease EC?

Once you understand how plants roots work, the answer is obvious.
They work in a very similar way to an R/O machine. So nutrition will flow from the higher EC to the lower EC in a reverse osmosis process.
Which means, if your EC is climbing, you need to increase EC to a level that stops it rising.
If you have hard water over 0.4, it may mean feeding with an EC as high as 1.8-2.0. This is something I wouldnt normally advise in DWC.

However, if you keep in your mind that a "normal" EC of 1.2 usually brings decent results in DWC, this should be the nutrient level on top of background EC.

With both guys who have had issues who contributed to this thread having high background EC's, I think this is the source of the problems. So being brave will pay dividends.

Remember, the key to this is what is happening to the water levels.
Good luck guys.
W

 

[myke]

Im normally around 1.4 ec,my 2 part nutes say 5 ml/l Ive gone to 4ml/l that was about 1.7 ec.Didnt get any burn but my ph kept dropping so I dropped back to 1.4.Im also in week 5 of flower so playing with ec can be trouble.
Do you use tap water?I do ,comes about 170 ppm pretty hard water.
Do you grow the same strain?If so try 1 in coco next run,easy to play around with ec as your watering so often.Or if your able to isolate one plant from your system.

 

[fartoblue]

Yes mate I use tap water with a background of 0.2ec. I have been feeding at 1.1ec including background which on reflection is pretty low even for DWC. I fell into the less is more trap after reading advice on Current Culture website when I first made my system, it seemed to make sense at the time and I just got into the less is more mindset.

Unfortunately I was plagued with root rot from my very first grow in the RDWC system so it threw me off track as I blamed everything on the rot.

I have now ditched all air stones but still recirculate into an epicenter but now top feed into 20 litre pots. The roots don't really hit tyhe water much until late veg or flip. Roots hitting the water wasn't planned it just happened. It's a bit like a Bubbleponics system.

I have today increased my feed ec to 1.6 inclusive of 1.2 background. We will see what happens over the next few days.

 

[myke]

How much calmag in ppm do u add?
My last res 6 days ago. 170 tap 100 Mg 100 Ca then food at 800.about week 3 I was at 1400 ppm so about 1000 food. Never gave it a chance as my ph dropped so much. I thought I had way too much food.i just added way too much ph down. When feeding that high you only need a little ph down. When I feed low I have to dump tons of ph down in.

 

[myke]

So whats going on?