Deficiency Help

[Thebeginning1989]

I need help identifying this deficiency. These are being grown in fox farm reused soil amended with nutrients; I also top dress accordingly. I PH water to 6.4-6.8, and only water when the pot is light (got a feel for an empty medium). When I do water, I water thoroughly.

I feel like something is missing in the soil as this deficiency is popping up in multiple plants. Going off diagrams, I am thinking magnesium. I wanted to see if I could get other more experienced to take a look. It is the discoloration on the edges of the leaves, and ribs (not correct term?) of the leaves.

Any help would be appreciated.

[BU2B]

I’m thinking you’re right.

[Blowdout2269]

I would agree with your magnesium diagnosis and possibly a little nitrogen. I'd make a tea with some Epsom salt and earth worm castings.

[Thebeginning1989]

Will do. I'll post back with the results after a few days.

[ZigZag]

If you've been measuring your runoff and its between 6.4 and 6.8 (as well as the nutrient water) then that's a good range for calcium and magnesium uptake. If it's there in the medium.
But if your potassium and phosphorus is too high then that can affect your plants ability to use calcium and magnesium even if its there. Also if your PH is too high it can reduce the plants ability to process nitrogen too. Thats why you still need some nitrogen even during flowering.
PH your runoff and test for mineral composition of the runoff. If either is off then try flushing the plants well to wash out all the salts and then add some nutrients back in at 1/2 strength. Hope it all works out!

[AGH]

Based on your post, I'm assuming that you're not using synthetic nutrients and you've gone the organic route (I only grow in soil and organic so good for you!). If this is the case, then read on! If this is not the case, feel free to ignore everything I'm about to write :-p

You mention you are pH'ing your water. In organic soil grows, 99% of the time you do not need to adjust the pH of your water. If you do adjust the pH, you cannot use the synthetic pH-up and -down. The chemicals in those damage/kill the soil biome. The soil biome is all that helps to make sure that your plants are getting the nutrients that they need and can cause a deficiency. So if you're pHing your water, you can probably stop, especially since the soil biome is amazing and it naturally buffers the pH to the correct level...isn't nature and organic growing amazing! When you learn to work with the soil and take care of it so it takes care of your plants, it's like an 'aha' moment! If you feel you must pH your water, do it organically with baking soda, vinegar/lemon juice, etc but know that if you're doing it, it's most likely because you're bored and not because your soil/plant needs it.

Secondly, if you're growing organic, you have to be very careful to not let the soil dry out like you might when using synthetic nutes. When that happens, all the amazing stuff in the soil (that soil biome of bacteria, fungi, etc) will die just like when adding synthetic pH up/down or synthetic nutrients. When this happens guess what? Yup! The soil biome can no longer provide nutrients to your plant because all that life in your soil dies and that results in nutrient deficiencies.

So, in organic grows, oftentimes the deficiency isn't due to there not being enough nutrients in the soil, rather the soil biome needs some TLC as opposed to adding more nutrients. The good news, both avenues can be pursued at the same time. You can take steps to nurture your soil biome while adding some amendments/nutrients AS LONG AS THEY'RE NON-SYNTHETIC as synthetic nutes will further damage your soil biome. Just remember, less is more and be patient during the recovery. It looks like you've got a strong start on your grow so with some chill and some gentle actions you have the potential for a great run!

[Thebeginning1989]

Is there an extreme in regards to not PHing? My tap water PH is about 8.4, which is the only reason I PH using citric acid. Using one 1/8 tsp knocks it down to 7.2-4, which I then fine tune down to 6.8ish. If I don't have to fine tune after that, that would be awesome, lol.

Also, I do have a question in regards to not letting the soil dry out. How do you personally keep the top soil from drying completely out between waters? I pretty much use the weight of the pot to determine watering, but I do find that the top soil dries out way before the rest of the soil needs a drench. I've thought about mulch or clay pebbles, but I I'm wondering if either would interfere with top dressing. I will admit I am guilty of letting the top soil get dry enough that it starts pulling away from the fabric pots in fear that if I keep the soil continually soaked I'd get root rot or something similar.

I really appreciate the response, and hope you see these two questions. I am always trying to learn more!

On a side note, I am learning going from clone/seed straight to 1Gallon has been hurting me (I'm sure it works for others). For some reason I can start them quicker, for longer, and healthier in solo cups before transplanting up. Shoot, some newer solo cup clones outgrew some of the older 1Gallon clones.

[AGH]

Personal opinion based on my experience: 8.4 is pretty high. EPA guidelines for tap water has a max of 8.5 (assuming your water is from a municipal source). If you're getting it down to 7.2 or 7.4 then I think you can trust the soil biome to handle it from there. Your next step is very scientific... f-around and find out! Try just getting it to the 7.3 range and see how the plants respond. My tap water is around that and the only thing I do is let it sit for about 24 hours to give the chlorine a chance to get out of there before I put it in the soil. If you really feel like f-ing around and finding out, leave the water as it is when it comes out of the tap and see how things go. Just keep good notes so you remember what worked and what didn't. If it were me, and I had multiple plants that were going to give me way more cannabis than I needed before the end of the next grow, I'd do one with straight tap water and adjust a couple to your 7.2/7.4 and if you really want to experiment, get one down to your 6.8. If you do this, let us know how it goes because that would be awesome!

There are a few ways to keep the top portion of your soil moist without overwetting the bottom of the pot. First of all, it looks like you're using cloth pots which will help a lot. Secondly, before you water, break the top portion of the soil up with your hands so that it's loose and soft. The top layer of soil can often become kind of hard and dry which prevents it from absorbing the water and that causes it to all pass through the top layer and get soaked up by the bottom. Third, when you water, do it in stages about 10-20 minutes apart. I will loosen the soil, slowly add half the water to all the pots, then wait a little bit before adding the second half. This gives that top layer of soil a little time to re-moisten and then really soak up and hold the second half of the water. Soil is kind of like a sponge. If you've ever had a super dry sponge that hasn't been used in a while and run it under the faucet, the water runs right off of it. But if you take a moist sponge and put it under the faucet, it does a much better job of absorbing and holding onto the water.

Also, when it comes to organic soil grows the watering regime is a little different than when using synthetic nutes. More frequent waterings with less water is better than less frequent waterings with more water. This is an article on GWE that I use as a guideline and it works pretty well (you have to scroll about 3/4 of the way down to see it) https://www.growweedeasy.com/are-can...red-how-to-fix

Lastly on your side note: After my seeds germinate (either in a glass of water or between paper towels or a combo of both) I put them in rapid rooters. Once the taproot shows out of the bottom of the rapid rooter, I put them directly into a 7-gallon cloth pot and have never had trouble. Of course, each grow/grower is different but a few things to keep in mind if going directly to the final pot: it may slow them down a day or two for them to get adjusted...but every time you transplant or up-pot, it slows them down as well. However there are two bigger issues to keep an eye on: how hot your soil is and watering practices. You need to make sure that your soil is well cooked and ready to go before putting your seedling into the soil so that the nutrients and soil biome are ready to go. If you haven't cooked your soil enough then the bacteria and fungi won't be ready to provide the nutrients in the soil to your plant and it may suffer as a result. And the real biggie: watering! Watering a small plant in a big pot can be tricky and you can easily under or over-water. If you follow the guidelines in the article above, you should be good. I've also learned that as the plant is little you occasionally need to add a little water around the outside of the pot further from the plant. This helps keep the biome chugging along and makes sure that as your roots grow, the soil is ready to nurture them.

All fun things that make organic growing a slightly different (and to me, more enjoyable) animal than using synthetic nutrients. No right or wrong way, just different!

[SoOrbudgal]

2 tablespoons of reg. Epsom salts in a gallon of water let it run out the bottom abit. Cheap quick solution