LED and humidity Vs HPS

[trixP]

I've grown year round indoor for over 20 years in the winters past I get small buds and really short plants that turn purple easy and grow real slow. In the summer I get stretchy tall plants with loose long buds nice trichomes like your never seen but the smell all evaporates by the time you get to the jar. Your house smells really loud doe . In the spring and fall was when I would have the nice buds that smell good and frost up.

In short through decades of trial and error I find the plants mostly like it in the mid 80s with humidity about 40 to 60%higher in veg and lower in flower.
View attachment 18966239

Yeah dude 20es user here my first groenim finaly doing and thanks to some people here we are fucking doing it trust me

I’ve learnt you can trully
Manipulate structure with light height I had big mothers I wanted to keep and have to flip them due to circumstances, I was very worried about the stretch needless to say I literally kept them maybe 4/6” taller

2 girls the orriginal runt BOOMED outta nowhere needless to say they are diff the runt had longer thinner colas and the smaller one the orrig stronger had FATTY BOYEEEES some fat like coke cans

I use a mixture of tradition and new school philosophy and it’s working for me I also have very nice lights and I’m there religious with the numbers needless to say I hiver always 75f-49-50rh always 1.3-1.5 vpd

What I did was 1.30 first few weeks and tapered 1.4 and now final weeks 1.50 humidifier kicks at 1.5

I actually raised my light getting signs of bleaching on the taller one and the smaller fatty she her leaves are closing even if she’s further16”. But I run 900-1200 ppfd literally 850/900 in the corner with the tent door open lol

Check your pms

 

[PoweredByLove]

I don't do led a lot like I said but when I first tried one of these new ones where all the leds are in a grid I got hella issues with the plants having severe micro deficiency about 3 days into switching. Couldn't figure it out at first. But the solution to that is just feed more food.

The real issue is the lights are too much. Led is intense up close but falls off fast. So if you find the top of your plants getting yellow just add more food. Or you could move lights up... But since led doesn't penetrate too much from where I was last time I tried em. It's prolly better to just up the food. The further you move light the less density you get on all the buds below the main tops.

Inverse blah blah blah law.

 

[trixP]

I don't do led a lot like I said but when I first tried one of these new ones where all the leds are in a grid I got hella issues with the plants having severe micro deficiency about 3 days into switching. Couldn't figure it out at first. But the solution to that is just feed more food.

The real issue is the lights are too much. Led is intense up close but falls off fast. So if you find the top of your plants getting yellow just add more food. Or you could move lights up... But since led doesn't penetrate too much from where I was last time I tried em. It's prolly better to just up the food. The further you move light the less density you get on all the buds below the main tops.

Inverse blah blah blah law.

Y’a i Feed full scale
Bottle, the light is still close just had it rly close about 2” up Gona get Mesuring tap and ensure each side for small tilt effect

 

[Terpyterps]

With enough exhaustion you can drop RH% to the same that it is in your home. If it is too high in your home then you need dehumidifier. It’s very plain and simple. You didn’t say what system you are going in, because if you grow in hydro it will make your RH% higher and you could get some B&W plastic sheeting and cut it in pieces and cover your hydro pots or if it is open system then cover it up. If you grow in soil you could cover the pots also or use mulch to keep the moisture in. If coco you could do the same thing than I recommend for hydro. For me too low RH% is issued so I need humidifier even in late flower. Lowest it gets is low 30’s and I like to keep it at 40% at late flower. Might let it drop to the 30% at last week or so.

You could run 150w LED and it would easily replace 250w HPS. Your temps will drop, not sure if it has any effect on RH%, might drop it a bit if it because evaporated water from your growing system. Might also lower transpiration of your plants if your grow space is hot.

 

[Rastafarout]

if get an led set go bigger with one that has a dimmer and high leds count
, dim down to 250 get a small dehumidifier and deduct these watts off the led
So -100w dehuey …you still get 150w light and moisture control
More yield will make up for bucks spent

 

[Rhizoma]

With enough exhaustion you can drop RH% to the same that it is in your home. If it is too high in your home then you need dehumidifier. It’s very plain and simple. You didn’t say what system you are going in, because if you grow in hydro it will make your RH% higher and you could get some B&W plastic sheeting and cut it in pieces and cover your hydro pots or if it is open system then cover it up. If you grow in soil you could cover the pots also or use mulch to keep the moisture in. If coco you could do the same thing than I recommend for hydro. For me too low RH% is issued so I need humidifier even in late flower. Lowest it gets is low 30’s and I like to keep it at 40% at late flower. Might let it drop to the 30% at last week or so.

You could run 150w LED and it would easily replace 250w HPS. Your temps will drop, not sure if it has any effect on RH%, might drop it a bit if it because evaporated water from your growing system. Might also lower transpiration of your plants if your grow space is hot.

Thanks for the answer.
I am in soil currently but thinking more and more about Coco...
Rh lung room 70-80% - 60-70% when dehumidifier on at night... Difficult to go below 50% for me, except playing a lot with how dry pots are...but did give good results...with RH below 50% my vpd is 2.02 so neither very good.... I am not able to control as I would like ( neithernwoth dehumidifier) the environment except slowly by days/weeks...no for example try to set up below 60% at 50-55% in week 5 flowering....more I can't do. If I run dehumidifier at light on and hps temps are 30c in 20min

 

[phunkeeboodah]

20% humidity in the grow space

 

[Terpyterps]

Yes, VPD is not THE most important aspect if looking into the other factors that also contribute to the growth. I haven’t been too keen about controlling it, but more importantly you should fall around the optimal range of environmental factors like temp and relative humidity. I find that VPD causes stress unless it’s automated because it is very difficult to keep on point manually like people do with PH and EC example. I have temps at 25-27c/77-80.5f and 40-45% RH and night time 17-20c/62.5-66f and 35-45% RH. I’m staying at the range that is “agreed” in basics. Just saying this because I saw that there is so many growers stressing that, but even in nature you never get the perfect deal and the plants adjust and they do just fine.

 

[growslow]

Hi all
I am considering moving to LED as I am struggling a lot with heat ( winter with a 250w HPS).
My main concern now is that I read that LED won't drop humidity down with light on as HPS does and consequently I will need a dehumidifier running 24/7durijg flowering.
Is this true?
It will be problematic having to add lot of watt on top of the LED to having dehumidifier light off and on.

Any clarification or advise much appreciated

Thanks
R

focus on the VPD if your temp drops your humidity will need to change I run a HLG Scorpion Diablo in a 5x5 in our testing tent and need my outside room below 60F (15.5C) to maintain the proper VPD in the tent and keep my temps below 80 as I do not run Co2. My exhaust fan is turned down to the min to maintain this perfect environment. I run a dehumidifier at night to accommodate cooler temps on and inkbird controller to turn it on at lights out, and I have duct tape over the display to block light. I focus on the temp outside the temp and use the fan for temp not humidity. I think your life will be easier but what do I know LOL works for me in the winter

 

[Rhizoma]

Many thanks!
I will move to LED this weekend hopefully and I will do 1 week vege andn12/12 directly.
Your comment will help me to see how manage drop in humidity with LED.
Thanks

 

[troutman]

I find the humidity only goes way up when the lights go out.

 

[trixP]

I find the humidity only goes way up when the lights go out.

When the ac infinity fans go off cause they can’t last 24/7

 

[hillbil]

Mold and mildew do not stop growing/spreading when the lights go out