LED lighting and deficiencies

[The Green Griffin]

those are some sexy pipes! is the cover the same piece from the cutout on top?

Yup! Waste not....want not! Btw, I’ve got a message into Grodan to try to get more clarity on this.

 

[The Green Griffin]

diy vero cobs I cant get mine to not stay green !!!!
Great idea when you start seeing deficiencies do a slurry test.
Dig down into your medium a couple inches and take couple Ozs of your medium and then mix with a couple Ozs of clean RO water.
Let soak for couple minutes and then test your pH and ppm its far more reliable then checking runoff because your just getting readings of all the crap flushed into bottom of pots. Take corrective measures with flushing not grabbing bottles of hope this works!!!!!
Me i use only Nectar for the Gods and photosynthesis+ so my medium needs to be in the 6.1-6.8 pH and works best with mediums ppm in the 200-500 range. They recommend flushing if seeing over 600ppm as its a calcium based line and relies soley on calcium uptake.
So when using high urea nitrogen based of course your gonna want your pH range close to what your feeding at, and to watch ppms for salt build up which will lead to quick lock out of nutes, though I'm not sure what the idea ppm in medium would be for nitrogen based uptake.
BTW these pics are all weeks 7-8
View attachment 4052895 View attachment 4052896 View attachment 4052897

Certainly agree that a slurry test would be more accurate in soil, but for rockwool checking the runoff should be very indicative of where the PH is, especially if you let the solution “perk” in the wool for a short time, then carefully collect enough from the cube to get a reading. Checking runoff from flushing is still valid, albeit directional since runoff will be a more of an average of the flush solution and root environment PH. With each flush, I see the runoff PH decrease and I continue flushing until I get with a couple of tenths of my target. Very surprised I am having such PH control issues since I never had the issue 15 years ago. Cant figure out any other reason than the rockwool since I don’t have salt build up or significant shifts in reservoir ppm/ph. Any thoughts?

 

[Yodaweed]

Certainly agree that a slurry test would be more accurate in soil, but for rockwool checking the runoff should be very indicative of where the PH is, especially if you let the solution “perk” in the wool for a short time, then carefully collect enough from the cube to get a reading. Checking runoff from flushing is still valid, albeit directional since runoff will be a more of an average of the flush solution and root environment PH. With each flush, I see the runoff PH decrease and I continue flushing until I get with a couple of tenths of my target. Very surprised I am having such PH control issues since I never had the issue 15 years ago. Cant figure out any other reason than the rockwool since I don’t have salt build up or significant shifts in reservoir ppm/ph. Any thoughts?

Evaporation can mess with PH, so can algae or dirty hoses/drip lines. I'd suggest running some hygrozyme and dripclean through your system, good luck.

 

[Unagi]

After reading the whole thread I'm not sure if you got this issue sorted out or not @DesertHydro.

Could your plants be rootbound? If you are using the same nutrient regime, enviroment and medium as you did with HID lights.

Im thinking the led lights might grow your roots faster then you are used to with HID.

My experience with deficiencies are connected to plants being rootbound.

Have you tried pulling the roots out of the container and checking them? Can do this after harvest aswell. I always check the roots after harvest, this helps give me an idea of what roots can look like on a healthy or unhealthy plant.

Anyway if you did figure out this stuff, dont mind my 2cents

 

[CobKits]

how'd you cut those so nice and straight? table saw?

 

[The Green Griffin]

how'd you cut those so nice and straight? table saw?

Yup. I set the fence 2” from the blade. If your fence is short you’ll have to adjust that distance to get the blade at 90d to the pipe. The toughest parts are 1) not letting the pipe twist. I would recco using two people, one feeding the pipe in and one on the outfeed AND be sure to put a mark at “top dead center” on both ends, and 2) the pipe tends to compress, so one continuous motion minimizes sawblade binding. In fact the kerf disappears after the first cut! You’ll also need to use GOOP or similar sealant/glue on the end caps since the radius of the tube reduces after the cut. Standard pvc cement won’t work. I also use Goop to fasten in the overflow pipe. I freakin LOVE Goop!

 

[mcnasty_nug]

Sorry I didn't read the entire thread, but I had issues when i first set up my LEDs. I switched my nutes to running jacks-calnit-magsulf. I run 3g jacks, 2.5gcalnit, and 2g mag sulf. Worked like a charm. Everything is super happy. I bumped my temps up some too to keep the leaf surface temp right.

 

[thetr33man]

Sorry I didn't read the entire thread, but I had issues when i first set up my LEDs. I switched my nutes to running jacks-calnit-magsulf. I run 3g jacks, 2.5gcalnit, and 2g mag sulf. Worked like a charm. Everything is super happy. I bumped my temps up some too to keep the leaf surface temp right.

does it matter what order u add these to the water? Is this in RO/distilled?

 

[mcnasty_nug]

does it matter what order u add these to the water? Is this in RO/distilled?

yes! from what I gather, you need to add the sulfates first. I do jacks, then mag, then calnit. I was told that the sulfates are like a glove to nitrates. If you add it last it will swollow up your nitrates and make them unusable. Im sure that is NOT whats happening scientifically but it was a good analogy i thought.

I used both RO and my well water.. Currently I just use my well water since it comes out at 50ppm

 

[Flowki]

Whats the runoff EC?
Reasons for a deficiency
The magnesium deficiency can occur because uptake is inhibited because of:

• A very wet, cold and/or acidic root environment.

This is exactly it I feel. Colder root temps from time of year/swapping from hps to cob and also sounds about right in a previous post that said lower temps and/or high humidity = less transpiration/cal uptake.

Probe placement and temp control will be dictated by root zone temps now, nothing else. Humidity control I guess will be dictated by canopy level temps, probably around 50-60%? assuming canopy temps will be pushing 80-85.

 

[hybridway2]

let's keep this thread up and current because this seems to be an issue that most are having. if someone solves the puzzle be sure and share the knowledge

Im only in the beginning of this hidden thread. And they say i am crazy???

 

[hybridway2]

May be too late for this harvest, but figured I'd chime in just in case someone sees this in the future.

That looks like a straight up Mag deficiency. Look at this chart https://www.alchimiaweb.com/blogen/wp-content/uploads/2015/12/KRuFnY4-1022x1024.jpg

The steps typically taken for fixing it:

1) Do a good flush to get the medium free of all built up nutes.
2) Feed half strength and add a Mag supplement. pH to at least 6.1 (or you can go up to 6.5 for even better uptake)
3) Don't look at old leaves, they won't likely improve. Look at new foliage to see if the problem is fixed.

Good luck man!

I have to do this 1/3-1/2 through flower on most plants. Generally works somewhat. But why. WTF already

 

[hybridway2]

LedDefficiency

 

[hybridway2]

LedDefficiency

Yup.
If this happens so much less (almost never in soil) what is the reason ?

 

[burnt r3ynolds]

Yup.
If this happens so much less (almost never in soil) what is the reason ?

Soil has higher cation exchange rate. Holds and buffers more cal mag iron ect. I use afew types of led and do regular Epsom salt foliars and add chelated iron once in a while. Don't have to under cmh or hid. Certain plants definitely want more magnesium iron calcium in my area under the LEDs then other types of light. It was a learning curve getting used to.