Get on Amazon, you can get a PH/TDS combo for $9 (though I can't vouch for the quality). I use one that cost $12.99. You can spend a lot more for lab quality. As long as you calibrate once in a while the cheap one I have works fine.
I think I have a magnesium deficiency
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Emilya Green
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I don't see a magnesium deficiency. I see an everything deficiency. I don't see that pH has anything to do with this. This is because you applied the granular nutrients to the soil, and then have only watered twice. You would have been much better served by starting in smaller containers and having to water more often, and then your plants would have been fed more often, every time the granules got wet.
As it is, you have watered twice, so you have fed twice. It shows. The plants are yellowing due to a lack of nutrients... of all kinds. You need to water more often. You should read my thread on how to water seedlings or small plants in large containers. There are ways to water more often and take advantage of the top set of roots, while you wait on the bottom roots to drain the water out of the container. You can't expect granules that are applied only so often to keep working, if you don't keep them wet, or at least wet them every 3 days or so.
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bobj
Well-Known Member
Okay, if I adhere to a schedule of watering every three days, how much water am I looking to use (on average) each time?
Emilya Green
Well-Known Member
a schedule won't work... it all depends on your roots, and this should change day by day as the roots get stronger.
I assume you are waiting on your plant to drain the water in the bottom of the container. You don't want to add to that stale water sitting there. So every 3 days, until the plant can finally drain the bottom, give maybe 2 cups of water. Dribble it all along the top surface and especially along the outer perimeter of the container... make the outside edges the wettest spots in there so as to entice roots to grow sideways out to get that water. Do this every 3 days until the container gets light and you know the plant has used all of the water.
Then, slowly water the entire container to runoff. It will take a lot of water... at least a gallon in a 5g container. Just to make sure, come back 20 minutes later and water to runoff again. Then, play the waiting game again. Don't water that entire container again until she can drain it... even if it takes a week. Every 3 days, lightly water the top surface and the edges.
As the roots get stronger, this cycle will speed up and eventually you wont need the inbetween waterings of the top and edges... the plant will be able to drain the fully saturated soil in 3 days and you will be able to start watering normally.
cbdhemp808
Well-Known Member
@Emilya, I don't think there's any Mg in his soil mix or fertilizer.
Emilya Green
Well-Known Member
Then it is funny that I don't see classic signs of Mg deficiency...
What I do see is a bunch of dormant microbes with dry soil up top so they can't work and the entire feeding cycle shut down due to lack of water.
cbdhemp808
Well-Known Member
Well it's true... the PROMIX he's using doesn't have any Mg source listed that I can see, and the PROMIX fert doesn't have any Mg listed in the analysis. Just saying... dunno where any Mg would be coming from.
Bob said yesterday:
So heck, he just hasn't been watering near enough. It's amazing the plants look that good. Keep in mind, he says the pots are draining just fine. Is the peat just holding onto too much water? Or is everything OK?
Bob said yesterday:
So heck, he just hasn't been watering near enough. It's amazing the plants look that good. Keep in mind, he says the pots are draining just fine. Is the peat just holding onto too much water? Or is everything OK?
Emilya Green
Well-Known Member
I gave detailed instructions as to how to water to save this grow up above. It has nothing to do with the peat and everything to do with the watering frequency and amounts. As far as the Mg goes, it seems unlikely that a nute line would not have any of this important nutrient in it, but lets address that when we see what looks like a Mg deficiency, with copper colored necrotic regions in the middle and ends of the lower and middle level fan leaves. I see instead a general overall yellowing, showing a severe shortage of a mobile macro nutrient, probably mostly K at this point, and I see that it is moving upwards on the trunk. The plant is doing everything it can to cannibalize whatever it can in order to keep supplying what is needed to build the buds.
cbdhemp808
Well-Known Member
Yep, as I said, he isn't watering nearly enough. From what I can see, PROMIX doesn't look like a very good product.
I'm not seeing a widespread serious problem as you are seeing. Where's Waldo?
I'm not seeing a widespread serious problem as you are seeing. Where's Waldo?
This thread that you started has become interesting.
Pro-Mix is a popular brand and a huge company in both the US and Canada. Last time I counted they made over 20 different products, all using Peat Moss as the major ingredient. It used to be someone could say Pro-Mix 'such and such' and everyone knew what they were talking about. Now it is a bit more complicated. Probably would not hurt to take a photo of the front of the bag/bale of what you are using for the growing medium and a photo of the fertilizer since saying "I used PROMIX's granular fertilizer (4tbsp of the 4 1/2 tbsp recommended dose)" makes it hard to figure out which one that is. Maybe that photo including the NPK numbers and the % that is soluble and insoluble which is usually on the back.
Because I think it will help the group relate to what is happening on your end, is the one gallon per 5 gallon grow bag or one gallon for all of them? Peat can suck up a lot of water and hold on to it for a long, long time.
Use a Calcium & Magnesium product as part of the fertilizing program. Even if it was a Magnesium deficiency the plant will take in the Calcium and make use of it. Plus, I get the feeling that our indoor growing under artificial lighting pretty much makes it a given that the Ca has to be added for most of the growing & flowering time. It is part of my planning ahead each time I look at my plants now.
The stuff will come in a liquid and only a few ml per gallon of water is needed. Or a liquid that is mixed at one ounce per gallon. Or, a powder that can be mixed with water or just used as a top dressing and each watering helps dissolve and move it into the root zone.
About a year to two ago there were some threads very similar to yours started by new growers that were running into the same sort of problem. The group was able to figure out a lot of what needed to be done to get those plants back on track.
Not necessarily. The plants we are growing are what I would call a heavy feeder. They demand more than the average Basil or Cilantro or Parsley plant. Plus once flowering starts the demands from the plant double or triple. Your plants look great. They are healthy and that some of the leaves are showing the beginnings of common deficiencies is an indication that they have already used a majority of the nutrients the manufacturer put into the mix.
Good looking plants so it should not be hard to get it figured out.
Enjoy the day.
cbdhemp808
Well-Known Member
Since Bob has only recently up potted, one possibility would be to re-pot using FoxFarm Happy Frog, or at least Ocean Forest. And then use the FF liquid ferts. If he can get FF locally.
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bobj
Well-Known Member
I cannot give you pics of the bag of soil I used, because I threw that away a long time ago. But I can give you photos of the fertilizer I'm using
I've used all three fertilizers in my pots. It's all the exact same: nitrogen, phosphoric acid & soluble potash, all in different denominations with some organic material tying it all together (supposedly it's soy). By mixing all three fertilizers together in equal parts I was able to make a somewhat close fertilizer of equal NPK values (close to 4.6 throughout). Nobody could tell me WHICH NPK value was of the utmost importance to a plant in veg., so I took matters into my own hands and made it equal.
I only added 4tbsps., not the 4 1/2 like what was prescribed on the package. I added 4 tsps. of each bag and mixed thoroughly in a measuring cup before applying to my soil. I have not added anything else, besides tap water.
PROMIX says they add trace secondary nutrients into their fertilizers, but which fertilizer? They also claimed on both the soil and seed starting mix packaging that it would feed for 3 months, I didn't even get 3 weeks of it lol.
Suppose to say, I think PROMIX is full of shit. BUT THAT'S OKAY, I'm capable of amending my soil as need be.
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bobj
Well-Known Member
The leaves have dark veins, that's not shadowing. I believe that's a sulphur deficiency. Also those leaves are long and spindly, another indication of a sulphur def. or zinc deficiency (I forget which one).Yep, as I said, he isn't watering nearly enough. From what I can see, PROMIX doesn't look like a very good product.
I'm not seeing a widespread serious problem as you are seeing. Where's Waldo?
Are all three of those nutes meant to be used together? Is there a feeding regime that the manufacturer recommends with those three products (together)? If’ I was you, I’d get a nute line for cannabis, and follow the directions to the letter. Sulfur deficiencies are pretty rare, particularly in store bought soil.
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bobj
Well-Known Member
Probably not, at least not in the sense that it explicitly states not to do so on the packaging.
But it's all the exact same material, the only thing I changed was the NPK value. All three fertilizers are literally comprised of the exact same compounds, just in different values. I can post pics from the back of the fertilizer ingredients of you don't believe me..
It’s not that the chemical formulas are the same, it’s that they have different ratios of NPK, and each of those has a specific time during growing that they should be used. Plants need more N in veg, less in flower, more P& K in preflower/flower.
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bobj
Well-Known Member
Oh okay, no there isn't a feeding regiment. I'm doing this one the hard way, I guess. Just apply to the top soil and water in. I was going to apply the fertilizer this way for veg (balanced formula) and then use the floweer and potasium fertilizer together for added benefit in flower (NPK would be 3.5 |5.5 |5.5 )
cbdhemp808
Well-Known Member
Hi Bob ~ There are a lot of factors going on. Leaf coloration is not a 100% indication of any deficiency (serious or otherwise), while necrosis (yellowing and dead areas or spots) can be caused by a number of things including deficiency. Sometimes there is genetic coloration going on, which is normal and not something to be "corrected". Sometimes particular strains may have a tendency toward particular deficiencies, while other strains do not.
One of my CBD phenos has a light/dark coloration on all of its leaves (below). That plant produces excellent buds and good yield. I've made many clones of clones of this plant, and it always grows this way. No other plant in my collection does this, and they are all growing in the same soil w/ the same nutrients.
I'm recommending you look at the overall health of your plants. If they are growing and getting bigger, and most of the leaves look relatively healthy and green, then keep doing what you're doing. Let it grow. But water more, and tune into the wet/dry cycle.
Again, if you could switch to Fox Farm soil and liquid ferts, that would likely be much better to work with. If not, it looks like you've got a good approach working with what you've got.
happy growing!
CelestialNurseries
Well-Known Member
Looks kinds like TMV...even though they aren't even sure cannabis can get it..Hi Bob ~ There are a lot of factors going on. Leaf coloration is not a 100% indication of any deficiency (serious or otherwise), while necrosis (yellowing and dead areas or spots) can be caused by a number of things including deficiency. Sometimes there is genetic coloration going on, which is normal and not something to be "corrected". Sometimes particular strains may have a tendency toward particular deficiencies, while other strains do not.
One of my CBD phenos has a light/dark coloration on all of its leaves (below). That plant produces excellent buds and good yield. I've made many clones of clones of this plant, and it always grows this way. No other plant in my collection does this, and they are all growing in the same soil w/ the same nutrients.
I'm recommending you look at the overall health of your plants. If they are growing and getting bigger, and most of the leaves look relatively healthy and green, then keep doing what you're doing. Let it grow. But water more, and tune into the wet/dry cycle.
Again, if you could switch to Fox Farm soil and liquid ferts, that would likely be much better to work with. If not, it looks like you've got a good approach working with what you've got.
happy growing!
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