These plants are just over 4 weeks old since they broke ground from seed. I am not sure why some of the leaves are yellowing. It is not like a typical nitrogen deficiency that I have had many times in the past - it is something different. I tried increasing the concentration of my nutrients but it hasn't seemed to help very much. The rest of the leaf gets greener but the yellow spots stay the same. Medium: Hempy buckets 4:1 Perlite:Vermiculite Light: 400w MH put on 75% power Tent: 2'x3' grow tent Nutrients: General Hydroponics with additives Strength: 2-2-1 Grow-Micro-Bloom plus additives at regular strength Temperature: Low 50F, high 75F Pot size: 1 gal pots with duct taped bottoms to help the medium from flushing out and to hold more water. Also has a drain hole 2" above. Any help is greatly appreciated. If you have any other questions about my setup please let me know. This is my first time with hempy bucket and it has been a bit of a draw back. My amended coco-perlite-soil plants are growing faster than these which I found surprising. Maybe I should just go back to coco-perlite. Whether using this medium for hydro or as a soil it has never failed me and I've only had great results. *** Ignore the couple plants in the background of the photo with chunky perlite - those are my soil plants
What's your PH at? The yellow will not go away, however as long as the new growth is healthy and green then you may have already solved the problem.
pH is approximately 6.0. I'm using a basic GH pH kit so it's really around 5.8-6.2. I have a pH meter I just have to buy more calibration solution... it goes through it like crazy.
looks like mg deficiency or early nute burn. Hempy is passive hydro and uses the hydro pH scale. I've read that for hempy specifically to water closer to 6.0 however I wasn't sure for which medium specifically this applies to. I run coco perlite hempies and not perlite/vermiculite.. I too am having a mg deficiency that looks kind of similar to this, except I'm also having a sulfur deficiency aswell. Check your runoffs pH. I just checked mine today and was shocked that it read 6.5 when I feed with always ph'd between 5.6-5.9, how could the runoff be higher?? I've been using a shitty pH meter most of the time because the dropper and test method takes so bloody long. One tiny drop too much of pH up or down and the pH will read 8.5+ or 4.5- I've only calibrated my meter once so perhaps I should get some calibration fluid and maybe that's where my problem lies as well.
Yeah there are definitely trade offs between the drop test versus a pH meter. With the drop test it is more accurate/consistent, cheaper, less maintenance but is harder to read and only shows a pH range instead of a specific number. The pH meter can be more precise and accurate but is more expensive and requries maintenance - batteries, calibration etc. The only thing I can think of would be a calcium/magnesium deficiency. But I do have 400 ppm tap water that I feed with. You would think it would have more than enough cal/mag in it but maybe not. Although I have heard that perlite holds in magnesium but I could be wrong? The new growth on my plants seem to have the same deficiency as previously.
Oh for sure. I don't own calibration solution and cleaner and all that. For awhile the dropper set was matching very closely to the meter so I decided to stop using both every time and just use the meter. I have not heard that about perlite, I thought it was actually that perlite doesn't hold on to anything and is a pretty inert medium. A lot of the PPM in tap water is not actually made up of the nutrients usable to cannabis, I mean it could be.. but there are other things in water that show up in ppm besides usable nutrients. I know my cities water ratings because I get some of the cleanest tap water in the country, and I still run calmag. For a temporary solution, if it is mg deficiency (which is my bet) then pick up some plain epsom salts and dissolve 1tsp into some hot water, (enough so it all disolves) and then add that to 1 gallon. So 1tsp/gallon but first dissolved. If you decide to stick with hempy I would recommend picking up calmag anyway, since I read that you have already used coco, which is also an inert medium which calmag is useful in. Another alternative would maybe be switch nutrients to coco specific. I've read that canna coco a+b has enough cal and mg in it already so you don't have to supplement like with other nutrient lines.
pH meters are usually only accurate when you calibrate them frequently. I also kept the tip/bulb of my meter submerged in a reference solution to keep it from drying out. Hmm I actually do have a bag of Epsom salt that I used to make a batch of super soil with. I think I'll take your advice and mix 1tsp/gal predissolved along with my usually nutrients. Too bad I just watered them last night I will have to wait a few days before I can try this. Thanks for that - I hope it works!
Yeah. Ph stuff is such a pain. I keep the tip submerged as well but in some water hehe. It was a 10$ meter anyway. Nice, post up if it works. Also dont be afraid to over water hempys. They have some of the most adequate drainage and can be watered even multiple times daily. I try to always keep water in the res. Epsom salt is literally magnesium sulfate and is quickly absorbable. If there is a mg def then hopefully you can see a difference fast.
Sounds good, i'll give them a feeding with it tomorrow and see how it goes. I'll post an update with some pictures in a couple days, hopefully they get better.
The update: the plants are doing much much better! I have given them a few feedings with 1-1.5 tsp Epsom salt per gallon. The deficiency is almost completely gone in the upper leaves, but still remains some in the lower leaves. The new growth is very healthy. One of the plants is super bushy too. They have started to really pick up the growth rate now that they are nice and healthy.