hm7 said:

Thanks for the confirmation on the pH. I'll keep an eye on the runoff here.

Temps are 76-78f, humidity sitting around 42-45% - so roughly 1.7vpd or thereabout. I'm coming up on the tail end up week 6 of flower here I think.

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Grownsince95 said:

At 78° and 42% rh you are at 1.90 kPa vpd which is about my high limit. While perfectly acceptable for late flower, lowering the EC of your feed to match those conditions would make your plants much happier. As you raise vpd you must lower EC.

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hm7 said:

Good to know, thanks! I wasn't aware that EC should be lowered as VPD increases, but it makes sense, as I understand the plant will absorb more due to VPD and how it affects transparation. I definitely do think that following the nute manufacturer's recommended amounts this run have been too much for sure in general. Now that I've got the runoff more in-line, I'll be sure to start backing off the nutes here.


Is there some kind of general guideline on how much to lower the EC when VPD increases?

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Grownsince95 said:

I run an automated drain to waste coco as well. If you want a quick check just shove 3 or 4 paper towels down into your bucket or whatever then squeeze them out into a clean container. Sometimes I just sit a fabric pot right on top of them.

People who say checking runoff numbers in coco is not important are mistaken. Just the fact that you have to "estimate" what's coming out is not a good place to start until you have your system down pat.

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hm7 said:

Hey everyone,

Hoping for some help here. It seems every run I do, I always run into the same issue at some point, but the more I do, the later the problems seem to start, so I suppose that's a good thing. Right now, everything has been looking excellent during Veg and early flower, but now that I'm in mid to late flower, I'm seeing some issues.

This is the first time trying CropSalt nutrients, so I'm following the manufacturer's recommend amounts (Flower nutrients - 5.1g A / 2.6g B). According to their FAQ, they suggest not adding anything else to them, including calmag, etc - so I've been trying to follow their recommended regiment. EC is sitting about 2.1, PH has been largely sitting around 6.0 (anywhere between 5.8-6.2, and I tend to leave it alone honestly). I'm using buffered coco, and right now watering 3x a day.

To my eyes, this looks like a calcium issue, and I also personally feel that the plant is showing signs of too much Nitrogen, as it looks really dark green/shiny to me, but again - first time running their nutes, I wanted to follow their suggested guide). I'm not really sure what to do at this point, nor am I really sure how to adjust their nutrients if needed.


I realize she looks pretty bad. Hopefully someone can help with some suggestions for future runs. I've got quite a few runs under my belt, but I still always end up with some kind of problem like this for some reason.

Thanks, much appreciated.

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