Help with increasing the humidity during winter?

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Phate008

Phate008

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Winter weather has started arriving in time for my second grow. Now I am dealing with very low humidity. My plants are week 6 of veg and haven't grown up very much. They are bushy but only about 14" tall. I raised my light to 24" and cranked it up to full blast. 2 days later I started seeing bleached looking spots on some fan leaves and the stems on the fan leaves started to split. I asked around and learned about VPD levels and found that I was way out of range with 80 degree F temp but only 40% humidity. I put my smart humidifier in the tent and set it to 60%. Its been running almost consistently but the RH has only gone up a little bit. The thermostat on the AC infinity exhaust fan and a secondary hygrometer are reading between 48-50% RH.

What are some of the best methods of raising RH? Towel in bucket? Bowl of water? Swamp cooler? What works for you guys during the dry cold weather?
 
freezeland2

freezeland2

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You should be fine at that rh. I’d be more concerned with the 80 degree temp. If you lower that a few degrees you’ll also get the added benefit of a rise in rh if your concerned about the rh. But that really isn’t a problem with where you are at.
 
Phate008

Phate008

53
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Yeah its tough. When I asked about my plants being short someone recommended that I put my light (Mars Hydro FC-E4800) to full blast and raise it a couple inches. That bumped my temps up to 80-84 degrees. In hindsight I should have put the driver outside the tent. I thought that with the cold weather, and the fact that my heat in my house makes things stay pretty cold, that I wouldn't have temp issues. Once I figured out that the issue was with VPD I have been scrambling to figure things out. I saw a thread on the bottom about clawing and tacoing plants and realized this must be somewhat common. Almost all my leaves on 2 plants are split down the middle. The leaves on one of the plants are clawing. Think this is from direct exposure from one of my fans for circ. Hoping if I can jump the RH up to 60-70 it may relieve the plants and then I can square away temps.

What are the optimal temps for veg and flower. Also what would be the optimal RH for these optimal temps?
 
freezeland2

freezeland2

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I try and target 78 degrees and an rh in the 50’s during veg. Flowering a couple degrees cooler and the rh as low as I can achieve. Like 35%
 
growsince79

growsince79

9,065
313
Winter weather has started arriving in time for my second grow. Now I am dealing with very low humidity. My plants are week 6 of veg and haven't grown up very much. They are bushy but only about 14" tall. I raised my light to 24" and cranked it up to full blast. 2 days later I started seeing bleached looking spots on some fan leaves and the stems on the fan leaves started to split. I asked around and learned about VPD levels and found that I was way out of range with 80 degree F temp but only 40% humidity. I put my smart humidifier in the tent and set it to 60%. Its been running almost consistently but the RH has only gone up a little bit. The thermostat on the AC infinity exhaust fan and a secondary hygrometer are reading between 48-50% RH.

What are some of the best methods of raising RH? Towel in bucket? Bowl of water? Swamp cooler? What works for you guys during the dry cold weather?
You need a programable ac infinity exhaust
 
Phate008

Phate008

53
8
You need a programable ac infinity exhaust
I have that. The problem is that it turns up higher in high temps and sucks the humidity right out of the room. I have the humidity and temp set, and it manages to get the temp lower around 78, but then I notice that the RH dips. I think moving the driver outside the tent may help a lot. It would lower the temp, the exhaust fan can go lower, and the humidifier can keep the RH steady.
 
growsince79

growsince79

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313
Are you venting outside? Can you just exhaust in the room? I have low humidity too but my plants don't mind too much.
 
m4s73r

m4s73r

89
33
I grow in the winter. With the furnace sucking all the humidity out the air its can be a pain. I keep my tents 75/60 during veg and 75/50 during flower. I find it easiest to keep heat the same. I use my AC fans to just run constantly at speed 2 and set my humidity controller to my desired rh.
 
Edinburgh

Edinburgh

2,692
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Humidity does not increase in winter the opposite happens and it gets real dry, some people run humidifier even in tent but indoor plants are not hardy, with exceptions, so this starts mold, I just let my plants work thru it, some don't mind others do, depending on strain. If you do run a humidifier keep as far away from tent as possible in a closed room, my rh is around 20% going as low as 16%, that's why your skin gets dry in winter low rh.
 
OldManGrower

OldManGrower

64
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Your first post seemed to imply that you were concerned that the height of the plant has not grown much, but it is bushy. What strain are you growing? I’m growing a Kush strain right now and am in my 4th week of veg in a tent. For my previous grows, my plants would be over 21” after week 2 or 3, and I would start flowering then, but my Kush plants are 16” however very bushy. That’s a trait of Kush plants, so maybe your strain is the same characteristic. So I’m starting flowering this week.
Temp at 80 degree in my opinion is too high. I also tried 78 - 79 but the plants didn’t like it and grew better at 75 or 76 max. My RH is about 40% right now and my plants are fine. Can you post some pics?
 
Aqua Man

Aqua Man

26,480
638
I think your hooped on the humidity man... you need to humidity the room the tent is in not the tent itself.... and no way would I want my house in the 50s personally.

So you can slow the exhaust to get the humidity up and prob bake your plant from heat.

Or... you max air exchange and bring those temps down.... that's what I would do as your not gonna want to humidify a big room in your house that's not built to specifically run high humidity.

From there a but less vigorous air flow if you have.... since that will increase the transpiration even more while your trading to reduce it.

Turn the lights down to 80% max at 24", 100% @24" is to much for them in veg.

This has little to do with your humidity and much more to do with your lights.

How many hours a day are you running in veg 18?

Man I found 3 different ppfd charts already good old Mars lying BS.
 
growsince79

growsince79

9,065
313
Your first post seemed to imply that you were concerned that the height of the plant has not grown much, but it is bushy. What strain are you growing? I’m growing a Kush strain right now and am in my 4th week of veg in a tent. For my previous grows, my plants would be over 21” after week 2 or 3, and I would start flowering then, but my Kush plants are 16” however very bushy. That’s a trait of Kush plants, so maybe your strain is the same characteristic. So I’m starting flowering this week.
Temp at 80 degree in my opinion is too high. I also tried 78 - 79 but the plants didn’t like it and grew better at 75 or 76 max. My RH is about 40% right now and my plants are fine. Can you post some pics?
My plants like 80-81 with leaf temps @ 79. I had a volunteer last year survived 118f @ 20%rh I don't think humidity is your problem.
 
Rooke

Rooke

1,342
263
Yeah just don't wanna drive em with mass light under those conditions. Usually don't handle it well.
Heya @ Aquaman just wondering if he would be better off running some T5’s during veg instead of the leds? When I start my plants to go outside I veg them for about 5 weeks with them and with I small humidifier in my 5x5 ft room I’m able to keep them at around 60% rh pretty consistently. But I don’t know if the growth rate would be more or less the same using the stronger light? I use 2 4 ft and 2 2ft sunblasters and if the room is cold I put my oil filled heater in the corner of the room with my oscillating fan on low and it keeps my temps in check for me. Babies love the humidity!!!
 
Aqua Man

Aqua Man

26,480
638
Heya @ Aquaman just wondering if he would be better off running some T5’s during veg instead of the leds? When I start my plants to go outside I veg them for about 5 weeks with them and with I small humidifier in my 5x5 ft room I’m able to keep them at around 60% rh pretty consistently. But I don’t know if the growth rate would be more or less the same using the stronger light? I use 2 4 ft and 2 2ft sunblasters and if the room is cold I put my oil filled heater in the corner of the room with my oscillating fan on low and it keeps my temps in check for me. Babies love the humidity!!!
Yeah hard to get the intensity with the... well not hard but need some decent ones. Definitely clones and seedlings though.

Honestly if it was me I'd be at 16" and 50% without looking at the plants as a ballpark. But if he is 24" I wouldn't be above 80% and even then I'm not to sure.
 
Phate008

Phate008

53
8
I think your hooped on the humidity man... you need to humidity the room the tent is in not the tent itself.... and no way would I want my house in the 50s personally.

So you can slow the exhaust to get the humidity up and prob bake your plant from heat.

Or... you max air exchange and bring those temps down.... that's what I would do as your not gonna want to humidify a big room in your house that's not built to specifically run high humidity.

From there a but less vigorous air flow if you have.... since that will increase the transpiration even more while your trading to reduce it.

Turn the lights down to 80% max at 24", 100% @24" is to much for them in veg.

This has little to do with your humidity and much more to do with your lights.

How many hours a day are you running in veg 18?

Man I found 3 different ppfd charts already good old Mars lying BS.

So having the humidifier in the tent is no good? I moved the lights further away to try and get the plants to stretch a little. Last night I moved the light to 22" and turned power to 80%. The lights have been on for the last 5 hours and the temp in the tent was at 72F and the humidity was 55%. I also put a little tray of water on the floor and it seemed like this helped in conjunction with the humidifier. Schedule is 18/6 currently. The airflow is an exhaust fan and 2 small clip fans from Amazon. I turned the light up a little just now because I am trying to get the temps closer to 75F. Going to post some pics now.
 
Phate008

Phate008

53
8
Your first post seemed to imply that you were concerned that the height of the plant has not grown much, but it is bushy. What strain are you growing? I’m growing a Kush strain right now and am in my 4th week of veg in a tent. For my previous grows, my plants would be over 21” after week 2 or 3, and I would start flowering then, but my Kush plants are 16” however very bushy. That’s a trait of Kush plants, so maybe your strain is the same characteristic. So I’m starting flowering this week.
Temp at 80 degree in my opinion is too high. I also tried 78 - 79 but the plants didn’t like it and grew better at 75 or 76 max. My RH is about 40% right now and my plants are fine. Can you post some pics?
At first I was worried about the height. At that time they seemed healthier, but I may have just been blind to the issues. The plants are all Square1Genetics. I have seen Canucks grow them and some of them stretched and were tall. I think my issue is the light. Last week my light was at 14" at like 50% power. Someone else recommended that I go 24" at 100% and this ended up causing a lot of issues. I plan on taking some cuts from the plants, but the stems on all the shoots are very thick and stubby. I wanted these shoots and the main stem to grow a little longer because I was unsure of how thick stems clones would take. I always read that you should clone bottom growth, but the bottom growth seems a little stunted. Trying to square away the temp, humidity, light distance and power. I think if I can find the right balance these will shoot up.
 
Phate008

Phate008

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Square1. Front left miracle mango, front middle GRCxBBC, front right Grape Rock x Banana Butter Cup x Forum GSC, back right GRCxBBC, back left Iced Wildberry
 
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