Excellent research Earl!

And an excellent read as well! This makes want to go out and get a humidifier so my VPD is in a good range. Now it is at 30% RH at 80F, thus VPD being too high?

It all makes plenty of sense. If the air is maxed out with moisture, how is the plant going to respirate?

And congrats on the stick! You really know your stuff.

Amazing Earl. Thank you so much! Your posts have clarified the basics of hydro to me better than several months worth of constant research.

Earl,

First off, great post. I had the same thing happen during my last grow. Just like you , I had not watered in a while and there was no leaks of any kind and yet to my utter amazement there was water pooled up on 2 leaves. At first I thought maybe my girlfriend had decided to give them a foliar spray and that the water I was seeing was from that. She said she had not touched them at all. So this has left me puzzled ever since, that is up until now. Thank you for answering a question that I really thought had no answer.
Shaughnny

Most plants will show some sex by the time they have grown past the 8th node. All these photos are of the 8th node, and that is where you should expect to see this phenomenon.

Sexing is done when the plants are in the veg growth stage, which is when the photo period is a minimum of 14hrs/day.

Once you know where to look, you will see this almost every time, on the 8th or 9th node.

Indeed a great post Earl. I've also suffered the mystery water droplets, but not often so I just let it bewilder me without worrying about it. Now I wish I had noted when it happened so I could then go back and cross-reference my notes to see what the humidity and temp were on those days.

I still can't figure out all the crazy math involved with VPD, it seems to me as though I should just keep the humidity at a pleasant level though

I agree about the math. It is a lot of effort.


There are four reasons why you should know the vpd in your grow room.

• High VPD (low humidity), is conducive to spider mites and other pest, and this can be measured and prevented, using the vpd calculator.

• High transpiration rates require a lot more water in the root zone, which is not a problem in hydro, but it is the reason we see the water pooling on the leaves.

• High vpd can sometimes mimick nutrient deficiencies in the leaves, and you should not start adjusting your nute solution to try and solve a problem that is caused by vpd.

• If you want to have the optimum growing environment for your plants, then you need to calculate and maintain proper vpd in your grow room. If you are not going to do this, then this is also another reason you should not be using full strength nutes.

For you Guys using GH nutes.Feed Chart


GH nute Calc

Love ya, man. Thanks for the links

Thanks everybody,

Here is a great link to a youtube video by Marijuana Man


Eye protection must be used when working with short-wave ,
and mid-wave UV light sources.
Damage to the eyes occurs from exposure to the shorter wavelengths of ultraviolet, known as UV-B (280-315nm) and UV-C (280nm and below).
Damage occurs in the form of photokeratitis (inflammation of the cornea), conjunctivitis, inflammation of the conjunctiva, and retinal lesions.






Where are my wealding goggles,
I gotta try this.