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First time grow in thirty years. Have problem with one plant which was the largest and very robust. last week tips of the leaves start to discolor turn brown. Other plants look better now. Water pH is good, soil is acidic,wondering if I have a K difficancy? Plants are 3 months old.Uploading: 15407515725859077648.jpg…
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looks like maybe too much heat or light is too close with leaf canoe shape and nutrient burn with tips of leaves burned
@Chungo I have had similar issues, and it was due to a myriad of reasons related to too close to the lamp, incorrect ph, and too much nutes. Good luck. If you want some of the experts to weigh in, you can help them with this support ticket.
Strain; Type, Bag seed, or NA:
Age from sprout:
Age from flower:
Soil in pots, Hydroponic, or Coco?
How often do I water and how do I determine when to water:
PH of runoff or solution in reservoir?
What is strength of nutrient mix? EC, or TDS.
Indoor or Outdoor:
Room size:
Light system, size, height from plants:
Temps; Day, Night:
Humidity; Day, Night:
Ventilation system; Yes, No, Size:
AC, Humidifier, De-humidifier:
Co2; Yes, No:
Any other info you think is pertinent:
These are 3 month old Green Crack indoors, in potting soil, water once a week run off PH is 4.5, Under 600 w LED X 2 at 24 inches. Room size is 4 X 6 x 8. Temp set at 26 C humidity below 50. I don’t thinks its the lights and I have been stingy with the Nutrients. I have flushed this plant with PH 6.45 h20 and then given a flush 4 days later with a 6-8-8 and added Mg and Cal with PH6.45 again. To see if I can get a change…Thoughts
A run off of 4.5pH is an issue. It should not be that low and likely a cuase of nute lockout. Do you have a TDS meter to measure the ppm or yuor runoff, as well as measure the ppms of your nute mix. Also, have you calibrated your PH meter recently? I use cheapos and I have come to they belief they need to be calibrated at least once a month if not more often.
If you still have it, look at the list of ingredients on your potting soil. It will validate if its a coco based “soilless” soil, or humus/compost based “regular” soil. If it’s coco based, pH needs to be around 5.8, if its soil 6.5. This was a big mistake I made in my first grow - wrong Ph = nute lockout.
Experts, I am trying to channel my inner bob31. Any insight?
@garrigan62 @blackthumbbetty
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Oh, I’m not an expert. Don’t list me with those guys! Lol!
I am really good at uploading stuff, though:
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You had me fooled then! I will bookmark this. Good stuff.
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Sixpackdad. Thanks as I checked the soil ingredients and it says Peat Moss, Bark and Peralite. I have been using this soil for 20 years to start garden plants and outdoor potting plants. I have not tested the soil or the run off for a week. However I use a cheap PH meter for the H2O going in I used a soil test kit which is a color code variety, and used the meter for the run off. The soil part of this I regretfully have over looked. Next grow I will try and correct this issue…Thanks
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Were would one get some Potassium Bi-carb as this helpful post uses it for correcting a low PH?..Thanks
Earth Juice sells granules. I use it as my regular pH up.
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OK. calibrated my PH meter and my H2O 6.6 going in after fertilizer added. Of interest is the same stems with the tinged leaves are still affected in their new growth. Other unaffected stems seem to have no burnt leaves on new growth. This TDS has me puzzled and I can’t find a good explanation of it in the forum as to its significance can you point me in the right direction…Thanks
With the TDS meter you want to measure two things. First is the measure of you water/nute solution. My well water has TDS ppm of 180 and then based on the nutrient schedule I add a certain amount of ppms of nutrients.
The second us measuring your runoff. When you water, you want to water enough to such that a lot of water comes out the bottom of the pot such that you can collect it in a cup. This runoff should be tested for ph and TDS ppm. You want you pH to be around 5.6 to 6.1 for soiless and 6.3 to 6.8 for soil. You want your TDS to be around 500 to 1500 depending on plant age. Over 2000ppms will hurt the plant.
Also, and I think I need experts to weigh in, but your soil is more soiless medium than a true soil. It is just peat moss, bark and perlite, and doesn’t have a compost material like humus making up a large part of it. If that’s the case you may want a slightly lower ph around 6.3 or so. You will also want to water more frequently, perhaps every other day to runoff. But I am not but 100% sure. Hope for more thoughts here.
If you can send along some latest pics
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Thanks 6 pack.
So do I have it right: I measure with TDS and measure the ppm prior to application then measure the run off to see if their is any up take? My farm water is Alkaline…thanks…
Yes,
I like ot take a baseline fo my original water. So, for example, I know my well water is going to be around 7.5-8pH and about 150-200ppms (175 average). After I add nutes and pH down, my solution is around 5.8 and 400 (I want about 225ppms on top of the 175). Then I meaure the runoff. I find my runoff to be about 5.9-6.4ph (varies plant to plant) and ppms from about 700-1100 (also varies by plants). This indicates to me my pH is ok and the “stuff” in my medium adds up to 525 to 925ppms. If the low range dips to low, I increase my ppms of my nutes; if it gets high, I reduce or go with only water a day or two.
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Thanks again. I have the PH somewhat understood but this PPM is lost. The addition of PPM from your grow medium has lost me in that I don’t know the significance of the increase? The increase is solids that are not absorbed ? So is there a max number of runoff before you get concerned and what is the significance of a increase of ppm on the plants? Thanks …
Now that you have pH understood, you are giving your plants the most opportunity to eat the ppms.
There’s isn’t an exact science to ppms. The theory is that if your water (or nute solution) going in has ppms of 200, and your runoff ppms of a 1000, then there is 800ppm of “stuff” in your medium. That “stuff” can be made up of nutrients that plant can use, other particles that don’t hurt the plant but provide it no value, and potentially harmful particles. Potentially, anything your plant doesn’t eat, plus the neutral and bad stuff, will build up in your soil. In addition to what is going in, the root interaction with nutrients also leaves behinds salts. At high ppm levels, all these good, neutral, and bad particles can all hurt the plant. All of this build-up can also impact the pH, too. The only way to remove the build up is to water to runoff such that they are carried out.
There are different philosophies on with the runoff should be, but there seems to be some consensus that you want it to increase as the plant matures. There’s lot of indication that having a runoff over 2000ppms is likely to start messing with pH and potentially causing lockout or nutrient burn/excess issues.
Some folks recommend flushing the plant periodically, especially in coco; and, also when you are transitioning from one nutrient type to another (veg/grow to flower/bloom for instance). I have only ever flushed for when the ppms got too high.
I have found that a sample of a the start of the runoff will differ in pH/ppm than a sample at the end. Try to be consistent in how you go about sampling runoff. There is no right and wrong - start, middle, end - you just want consistent sampling techniques. I am a middle-end-ish person.
I have been in veg phase recently, ppm-ing in around 400-500 and getting back from my plants 700-1100 for example. If that 700 becomes closer to the 400-500, that’s an indication my plants eating faster than I am feeding it and I need to ratchet up the food; if the 1100 starts to creep further up, that’s an indication of build up and I may want to consider flushing or lower my food.
Another caution is that ppms measurement is not necessarily an indicator you have all of what you need. Your ppms may be reading fine, but you could be running short of something like calcium and magnesium, which is common. So, even if your pH and ppms look aces, always be on the lookout for leaf symptoms.
@garrigan62 has a lot of great posts on ppms and ph. Here’s one that I like
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solid info brogan