LED lighting and deficiencies

Had the EXACT same problem. Soaked 4” cubes for several hours in 5.5 ph quarter strength nutes so thought I’d prepped properly. Using them in bottom flood tubes with nutes at 5.8. Jacks 321, RO water with CaliMagic and Mammoth P. Reservoir PH stayed relatively stable but the nutrient deficiencies just kept getting worse. Finally pulled a plant and squeezed some solution from the cube and tested. SIX POINT NINE. Yup 6 point friggin 9! Never had this problem in the (distant) past using the same technique. Growmau5 said that the recco from Grodan has changed, they now recco soaking TWICE prior to using. The fact that I’m irrigating only an inch or so and from the bottom kept the cubes from self flushing hence the rise in cube PH without the subsequent increase in the res PH.

With proper cube prep my method should be back on track. Thanks to all in this string for their perspectives and input, great thread!

I am running 3.25g Jacks 5-12-26, 2.4g Calcium Nitrate, 1/2 teaspoon Magnesium Nitrate, and 2.5 ml Thrive Alive B-1 per gallon with PH at 5.8.

Here are three different strains that I started cloning 20 days before this picture.

Here are some more clones feed the same thing under the LED lights for 5 days. I started these clones on the 17th of last month. One picture shows the clones when I put them in cups on the 26th and the second is when I put them in gallon pots yesterday.

These are Cherry Pie clones.

I was recommended dissolvine ecal which is a calcium supplement that doesn't add nitrogen. Gonna start adding 50-100 ppm to my RO water first before the nutrients. Should do the trick for the calcium hungry cob plants

ichabod crane said:

Here are some more clones feed the same thing under the LED lights for 5 days. I started these clones on the 17th of last month. One picture shows the clones when I put them in cups on the 26th and the second is when I put them in gallon pots yesterday.

These are Cherry Pie clones.

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Great looking clones...amazing for only two weeks.

The Green Griffin said:

Great looking clones...amazing for only two weeks.

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I credit the B1 and bright ass LEDs. I have 200 watts of Samsung 561c S6 28 inches over them. Run at 107 ma.

The other plants above are from the 8th or 9th. So they are 8 or 9 days older.

DesertHydro said:

I was recommended dissolvine ecal which is a calcium supplement that doesn't add nitrogen. Gonna start adding 50-100 ppm to my RO water first before the nutrients. Should do the trick for the calcium hungry cob plants

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I was warned to watch closely for any signs of nitrogen overdose with CaliMagic as well. From what I can gather, most have no issue with that but I’ll sure keep an eye on it....

The Green Griffin said:

I was warned to watch closely for any signs of nitrogen overdose with CaliMagic as well. From what I can gather, most have no issue with that but I’ll sure keep an eye on it....

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If you are worried about Nitrogen in your Cal/Mag use this one. It is made with Calcium Carbonate, Magnesium Carbonate and acid. It will lower your PH so you will need to watch out for that. I think it is 4 PH out of the bottle.

The Green Griffin said:

Yup 6 point friggin 9! Never had this problem in the (distant) past using the same technique. Growmau5 said that the recco from Grodan has changed, they now recco soaking TWICE prior to using.

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i wonder if they changed the manufacturing process. i soaked 10 4x4x4 cubes in a bucket of 5.2 last night the water was 6.6 this morning.

6.9 isnt too bad though at least its basically neutral. you should be able to compensate by dropping your res ph a few points, and maybe top flush cubes a few times

ichabod crane said:

If you are worried about Nitrogen in your Cal/Mag use this one. It is made with Calcium Carbonate, Magnesium Carbonate and acid. It will lower your PH so you will need to watch out for that. I think it is 4 PH out of the bottle.

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how is that as a foliar? readily absorbable? is it chalky/messy?

CobKits said:

how is that as a foliar? readily absorbable? is it chalky/messy?

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I dont know I dont do foliar. Two other things it has in it is 10% fermented molasses and 2.5% cane sugar.

ichabod crane said:

Two other things it has in it is 10% fermented molasses and 2.5% cane sugar.

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everything ive studied indicates that sugar is only beneficial in a soil environment

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

CobKits said:

i wonder if they changed the manufacturing process. i soaked 10 4x4x4 cubes in a bucket of 5.2 last night the water was 6.6 this morning.

6.9 isnt too bad though at least its basically neutral. you should be able to compensate by dropping your res ph a few points, and maybe top flush cubes a few times

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Not sure if they changed the manufacturing process, but it sure seems more stubborn at keeping a high PH than it did 15 years ago. I’ll soak at least twice from now on.
Yup, flushing each cube with 5.3 water (at 1/2 strength nutes) several times is exactly what I did. They are looking better and starting into the big stretch now.

OneHitDone said:

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lies!

just soak any current product overnight and you'll see the pH of the water rise significantly. there may not be limestone but the cubes are certainly alkaline

CobKits said:

lies!

just soak any current product overnight and you'll see the pH of the water rise significantly. there may not be limestone but the cubes are certainly alkaline

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Take it up with Everris bro

i think he'd out-enthuse me lol

CobKits said:

lies!

just soak any current product overnight and you'll see the pH of the water rise significantly. there may not be limestone but the cubes are certainly alkaline

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Agree wholeheartedly. This guy is flat out wrong! Unless my Grodan rockwool is ancient old stock, and I doubt that since I bought it 6 months ago. Does this plant look healthy? NOOO! Droopy, sad stunted growth with several nute deficiencies even though the reservoir nutes were near perfect and at 5.8 PH. No vigor. Here is the same plant 10 days later after flushing 4 times over two days with 5.6 PH solution with 1/4 strength nutes. Initial runoff was 6.9 @ the same ppm as the reservoir, (which tells me I didn’t have salt build up) finished at 6.0 after flushing. Soooo.....Based on my experience not presoaking will seriously hurt your plants. For gods sake, I am having to soak TWICE to keep from chasing PH thru the entire grow! If there is another explanation I’m open to discussion but I can’t think of anything.

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