Growing is much better - But still having problems

Well I’m into my 3rd DWC grow now and getting defintely more comfortable with it. Last grow produced 3 decent plants. While not producing the primo shit I’d hoped for I did get 11 oz. good smoke an unexpected benefit snuck in. As i waited for the trichomes to develop a few ambers ( and it seemed like I waited forever) the plants self-fertilized. So I’m not going to need to hit the seed banks ant time soon.

But on to the current grow.

I altered the environment some this time around as the 4 seedlings were maturing enough to transplant. Out of the last grow I definitelydiscovered that 4 plants in a single 3.5 gal reservoir led to some nasty overcrowding inside and outside the bucket, see-sawing pH and high fluid temps. So this time I shunted 1 plant (a Purple Haze) into a 3.5 gal bucket with one 6 inch net pot. Next to that I’ve got a 5 gal. reservoir containing 3 more plants (1-White Russian, 1-Gold Leaf and 1-Amnesia Haze).

All are growing quickly with the 3 plants in the larger reservoir are catching up quickly. All have or are developing large and very white root systems.

However, the single palnt (purple haze) has always had yellow spotting on the leaves and brittleness/yellowing at the tips and around the serrated edgesj of the leaves. There has also always been some reddish/purple coloration to the upper level petioles attributable, I thought, to the strain.

It’s time for solution change so I am going to give a cal-mag boost and see if that helps. That plus any recommendations I can get from this post.

Best wishes everybody, and keep on toking.

Uploading… Uploading…

Maybe a little phosphorus @garrigan62, @DonaldJ what do you think, @MacGyverStoner, what do you think as well?

The first pic I believe is… sulfur deficiency
Mix 1-2 teaspoons of Epsom salts per gallon of water until condition improves.:

His last photo looks to be:

Problems with Magnesium being locked out by PH troubles

Light Acid Soils, soils with excessive potassium, calcium and or phosphorus


Magnesium gets locked out of soil growing at ph levels of 2.0-6.4
Magnesium is absorbed best in soil at a ph level of 6.5-9.1 . (Wouldn’t recommend having a ph of over 7.0 in soil) anything out of the ranges listed will contribute to a Magnesium deficiency.

Hydro and Soil less Mediums

Magnesium gets locked out of Hydro and Soil less Mediums at ph levels of 2.0-5.7
Magnesium is absorbed best in Hydro and Soil less Mediums at ph levels of 5.8-9.1
(Wouldn’t recommend having a ph over 6.5 in hydro and soil less mediums.) Best range for hydro and soil less mediums is 5.0 to 6.0. Anything out of the ranges listed will contribute to a Magnesium deficiency.

Solution to fixing a Magnesium deficiency
Any Chemical/Organic nutrients that have Magnesium in them will fix a Magnesium deficiency. (Only mixing at ½ strength when using chemical nutrients or it will cause nutrient burn.


Sweet thanks my friend help is appreciated

I was talk’n with MacG yesterday and he also learned from this guy Jorge Cervantes.
But yup know you get to put a fase with me when we talk.


Lol that’s always a good thing haha, and that guy is smart lol always learn something different or useful in his videos

I’d look at this plant in my DWC bucket and imediately check my res temps and ppms 2 things are jumping in my mind rightnow with this plant ph fluctuation and root rot/stem if temps and ppm were good airstone is boilling water I would go to just incase h2o2 precautions. This is because these plants are seriously looking like root rot or a toxicity to me though in hydro silica and cal-mag are always a suspect for being deficient :wink:

Just an FYI guys, although I give credit where credit is due and Jeorge Cervantes has made a huge impact on society’s acceptance of cannabis, he doesn’t always have the most accurate science when it comes to cannabis, I really prefer Robert Connell Clarke and Ed Rosenthal, overall.



Ed Rosenthal is great too, I have 6 of his books read all of them 6 times start to finish and I’m in your page, id follow Ed Rosenthal a lttile more than jorge cervantes, thanks for pointing that out though great information for other people here :+1:

Robert Connell Clarke is one of the best though, one of his most famous books was originally his college thesis at the University of Berkeley.


I’ll buy some of his books, thanks to your advise :wink: thanks for the pointer buddy

What’s the name of that book buddy

I believe that one is titled “Marijuana Botany, An advanced study: The Propagation and Breeding of Distinctive Cannabis”, but he has since made many more books, I believe in cooperation and conjunction with other experts in the California medical scene.

another resource I like to hit not supporting the competitors just believe in using all resources at hand

Yea I’ll check it out tomorrow thanks buddy, I appreciate it and I use all opinions to my advantage :smile:

Thanks MacG I’m gunna look into buying a few of his books tomorrow, I greatly appreciate it

back on topic and the original poster’s questions:

The pH swing is likely a contributor. And of course reservoir temps and dissolved oxygen levels as a result of temps is important, but the roots do look very white.

Different strains can be more or less sensitive to pH fluctuations or PPM concentrations, just an FYI to think about.

The cal-mag supplement should help with any magnesium deficiencies.


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The I’s have it

Just to add. I too believe the PH seesawing is your main issue. Off PH allows for some mineral uptake to be blocked while allowing others to be too available.

Also; I would get those plants in individual buckets immediately. Once the tap roots intertwine; You are going to catch hell separating them :slight_smile:

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Hey everyone,

Thanks so much for the input.

I took a little time to post this to allow the plants to show real change. MacG, I don’t know what the cause but the pH whip sawing stopped. Why or how? I don’t have a clue but it has been right at 5,8 +/- 1.0 for right at a week in both reservoirs. The pics will show the growth since the earlier pics very plainly.

These pics are a couple of days old. In the meantime the upper canopy has greened up nicely with only minute yellowing in the center of the leaf. There’s vitually no browning or brittleness at the tip or along the serrations at the side of the leaf. As I changed the solution in both reservoirs I did notice something odd. The leaves, while brightly green felt dry and almost brittle plus you could hear them rustle and rattle when moved.

I added a cal-mag suipplement after changing the reservoirs and as of today (4 days after the initial pics) the leaves feel much more supple and pliable but still feel a bit dry, especially the larger fan leaves. That’ another question but some of the fan leaves (particularly on the purple haze and white russian) have grown to 6 in. x 4 in. and are seriously shading some of the lower growth. Anybody have a thought on that? I’ve heard leave them and remove them argued equally strongly.

Peace and keep on toking!

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