Is this cal mag deficiency or something else

[cbdhemp808]

The containers are about 50l or 13 gallons according to the conversion tool. The top layer is fungus gnat sand, as i had an infestation early on, but is now under control since i added the sand. The vast bulk is a compost mix equal rations of mushroom, chicken and cow manure. Its had a coco brick and a couple of small bags of peat to adjust the ph down. 5l bag of perlite or 1.3 gallons.

Thanks.

My opinion is that saving these plants is possible, but not going to be super easy. I think your plants are suffering from nutrient deficiencies and possible water issues. These two things need to be taken care of before considering other possible problems. I personally wouldn't use any fungus gnat sand. Instead, I would use a neem and soap solution as a spray to eliminate any bugs as needed.

Nutrients and Soil

My approach on making a custom soil mix is to have a base of compost, and then add to that specific ingredients to meet all the nutrient requirements of cannabis. By "compost" I mean a compost created from topsoil, kitchen scraps, dry material (e.g. straw), and worms – broken down and aged. Whatever commercial product could approximate that would work.

My recommendation is to transfer the plants to 5 gal black plastic nursery pots, and use different potting soil. You have two ways to go on the soil: 1) use a commercial soil like Fox Farm Happy Frog, coupled with their veg and bloom liquid nutes, -or- 2) make a new custom soil. Since your pots are so large, this may make the transfer a little difficult – you will need to take care to minimize damage to the roots. My guess is that you'll find that the root mass is fairly compact, because the plants are also compact.

To make a balanced custom soil, you need to include all the nutrients that cannabis needs, and enough of them. These are NPK and the micro-nutrients. Beside Ca and Mg, include all of these required micro-nutrients... boron (B), copper (Cu), iron (Fe), manganese (Mn), molybdenum (Mo), sulfur (S), zinc (Zn). Deficiency of N, and S as well, will result in yellowing. Fe, Zn, Mn are interrelated plant nutrients affecting uptake/use of N and S. So, you can see that all these nutrients are very important.

I use specific organic ferts in my custom soil mix, to meet these needs. Check out the link in my signature. I have also added kelp meal to that list, for more iron (Fe), and silicon dioxide powder as well.

If you decide to do a new mix, use a compost base and one concentrated N source (e.g. composted chicken manure, with minimal fillers). To this add plenty of coco coir (no peat moss), some perlite, and worm castings. And then find dry organic fertilizers to meet all the other nutrient needs. I also highly recommend adding mycorrhizal fungi in the hole when you transplant (I use a product called Mykos).

Water

In the smaller pot size, it will be much easier to provide the right amount of water, and to follow a wet/dry cycle, which is very important. Water until you get runoff, and catch the runoff in saucers. Remove water from saucers. Then allow the soil to dry, by testing the weight of the pot. This typically takes about 3 days, but varies depending on how big the root mass is.

Use the purest water you can get (I use rainwater), with near neutral pH. I recommend at least using filtered water, with chlorine removed.

*****

Here's the link to my perpetual grow, if you'd like to check it out:

Quest for mold-resistant strains, Hawaii outdoor greenhouse grow

Greetings Growmies, Regarding mold-resistant strains... I've done a bunch of research over the past few days, looking for available seed for strains with the following qualities: ✔️ high levels of myrcene (or already known to have high mold-resistance) ✔️ have blueberry or white widow genetics...

www.420magazine.com

 

[Two Scoops]

Thanks.

My opinion is that saving these plants is possible, but not going to be super easy. I think your plants are suffering from nutrient deficiencies and possible water issues. These two things need to be taken care of before considering other possible problems. I personally wouldn't use any fungus gnat sand. Instead, I would use a neem and soap solution as a spray to eliminate any bugs as needed.

Nutrients and Soil

My approach on making a custom soil mix is to have a base of compost, and then add to that specific ingredients to meet all the nutrient requirements of cannabis. By "compost" I mean a compost created from topsoil, kitchen scraps, dry material (e.g. straw), and worms – broken down and aged. Whatever commercial product could approximate that would work.

My recommendation is to transfer the plants to 5 gal black plastic nursery pots, and use different potting soil. You have two ways to go on the soil: 1) use a commercial soil like Fox Farm Happy Frog, coupled with their veg and bloom liquid nutes, -or- 2) make a new custom soil. Since your pots are so large, this may make the transfer a little difficult – you will need to take care to minimize damage to the roots. My guess is that you'll find that the root mass is fairly compact, because the plants are also compact.

To make a balanced custom soil, you need to include all the nutrients that cannabis needs, and enough of them. These are NPK and the micro-nutrients. Beside Ca and Mg, include all of these required micro-nutrients... boron (B), copper (Cu), iron (Fe), manganese (Mn), molybdenum (Mo), sulfur (S), zinc (Zn). Deficiency of N, and S as well, will result in yellowing. Fe, Zn, Mn are interrelated plant nutrients affecting uptake/use of N and S. So, you can see that all these nutrients are very important.

I use specific organic ferts in my custom soil mix, to meet these needs. Check out the link in my signature. I have also added kelp meal to that list, for more iron (Fe), and silicon dioxide powder as well.

If you decide to do a new mix, use a compost base and one concentrated N source (e.g. composted chicken manure, with minimal fillers). To this add plenty of coco coir (no peat moss), some perlite, and worm castings. And then find dry organic fertilizers to meet all the other nutrient needs. I also highly recommend adding mycorrhizal fungi in the hole when you transplant (I use a product called Mykos).

Water

In the smaller pot size, it will be much easier to provide the right amount of water, and to follow a wet/dry cycle, which is very important. Water until you get runoff, and catch the runoff in saucers. Remove water from saucers. Then allow the soil to dry, by testing the weight of the pot. This typically takes about 3 days, but varies depending on how big the root mass is.

Use the purest water you can get (I use rainwater), with near neutral pH. I recommend at least using filtered water, with chlorine removed.

*****

Here's the link to my perpetual grow, if you'd like to check it out:

Quest for mold-resistant strains, Hawaii outdoor greenhouse grow

Greetings Growmies, Regarding mold-resistant strains... I've done a bunch of research over the past few days, looking for available seed for strains with the following qualities: ✔️ high levels of myrcene (or already known to have high mold-resistance) ✔️ have blueberry or white widow genetics...

www.420magazine.com

Thanks for your input.

I transplanted to smaller pots this morning. I almost went the neem meal route in the top layer of soil this grow, didnt think of it till i had the gnat problem. I already had some gnat sand from the previous grow so i figured i would just use that.

I think most of the stuff i have in the existing mix is ok, but i think my ratios are off. It definitely needed more perlite for drainage. I had bought 5 litre bags thinking it would be enough, but mixing the volume of soil i had they ended up amounting to not much. Certainly not 20% as a previous poster had suggested. But i fixed that in the smaller pots i have made up, definitely much more free flowing now.

Will give them a few week to see if they spring back

 

[seaofgreen18]

Thanks for your input.

I transplanted to smaller pots this morning. I almost went the neem meal route in the top layer of soil this grow, didnt think of it till i had the gnat problem. I already had some gnat sand from the previous grow so i figured i would just use that.

I think most of the stuff i have in the existing mix is ok, but i think my ratios are off. It definitely needed more perlite for drainage. I had bought 5 litre bags thinking it would be enough, but mixing the volume of soil i had they ended up amounting to not much. Certainly not 20% as a previous poster had suggested. But i fixed that in the smaller pots i have made up, definitely much more free flowing now.

Will give them a few week to see if they spring back

Howdy you can Brew a Neem seed meal tea for gnat issues in the future they seem to not like it. Turns into azadactrine in the soil thrips don't like it either. Don't use air stones can't get them clean and they get loaded with bad microbes use the air lift method or vortex method Good luck I think what you did above will help send you in the right direction

 

[seaofgreen18]

“WATER ONLY SOIL RECIPE: (This makes a little over 30 gallons or 4 cubic ft of soil)

15 gallons sphagnum peat moss

10 gallons aeration amendment (pumice, perlite, lava rock, etc...)

5 gallons high-quality compost or earthworm castings (very important for proper nutrient cycling)

Add one Regular KIS Nutrient Pack and mix thoroughly and then water to field capacity. Turn the soil the following day then every other day for 7-14 days. When the soil has cooled to ambient temperature it is ready to plant in. It’s easiest to mix on a slab, tarp, or kiddie pool as not to lose any ingredients when adding water.”

 

[seaofgreen18]

“WATER ONLY SOIL RECIPE: (This makes a little over 30 gallons or 4 cubic ft of soil)

15 gallons sphagnum peat moss

10 gallons aeration amendment (pumice, perlite, lava rock, etc...)

5 gallons high-quality compost or earthworm castings (very important for proper nutrient cycling)

Add one Regular KIS Nutrient Pack and mix thoroughly and then water to field capacity. Turn the soil the following day then every other day for 7-14 days. When the soil has cooled to ambient temperature it is ready to plant in. It’s easiest to mix on a slab, tarp, or kiddie pool as not to lose any ingredients when adding water.”

Simple starter recipe