Plants Dying and Humidity not raising

I operate a 4x4x6 grow tent with a 400 cfm fan and filter combo and a 600w MH light currently. Plants are 2 weeks old. Humidity in tent is stuck in 30s and temp is high 70s. Plants are becoming lighter green throughout, not growing well, and leaves are curling in multiple directions, some are curling down. Fan is clipped to blow between canopy and light, two fans on floor, one near vent to help bring in air.

I recently added 1 gallon humidifer that isn't managing to raise humidity above 40.

Can you slow the exhaust fan down? The slower it goes, the hotter it gets? Edited with another question, do you run your circulation fans all the time?

Pictures help a ton, you say 2 weeks, have you fed them anything? What medium are you growing in? What size containers? Your humidity might not be ideal, but folks grow in deserts too, sounds like more than a low humidity problem to me

FruityHigh said:

I operate a 4x4x6 grow tent with a 400 cfm fan and filter combo and a 600w MH light currently. Plants are 2 weeks old. Humidity in tent is stuck in 30s and temp is high 70s. Plants are becoming lighter green throughout, not growing well, and leaves are curling in multiple directions, some are curling down. Fan is clipped to blow between canopy and light, two fans on floor, one near vent to help bring in air.

I recently added 1 gallon humidifer that isn't managing to raise humidity above 40.

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How high is your light over these? I grow under 600 HPS and that's a lot of light. My clones and younger plants at least 2' away minimum.

Fans run 24/7. Lights run 18 / 6.

It appears there may be some root rot? I do give them hydroguard weekly but I also know it isn't a catchall solution for root problems. As well, pH in the water today was 7. I lowered it

Here are pictures of the setup (humidifier that isn't doing fuck all on high blast is in lower lefthand under clipon fan), 4 plant children, and roots.

I would suggest trying a still period on the circulation (wind creating) fans. My plants grow much faster, circulation fan on 4 times per 24 hour period for 1 hour each. It is said the plants develop a higher humidity bubble surrounding them during the still periods. Your tent has an exhaust at the top, yes? During stiller periods, heat rises, and it can be exhausted if the exhaust outlet is mounted at the top.

Humidity is still not raising despite the humidifer on 24/7 and plants are beginning to get more yellow. This is very concerning and I'm not sure what to do.

You need to humidify the whole room the tent is in with a whole house humidifier.. Your air is getting exchanged as fast as it gets humidified in the tent. If the intake humidity is high then you will have humid air as it is passing through the tent. In any event plants should be able to handle high 70's and 30% humidity without wilting. You may have another problem like nutes.

I doubt humidity is your problem.

I'm trying to isolate the problem. They are in really rough shape.

Roots should be bright white, not brown. From the photos it looks like you have some algae in there. Rez change and disinfect, h202 if you're running sterile. Add more airstones or increase pump pressure to get more oxygen into your solution.

CK

captiankush said:

Roots should be bright white, not brown. From the photos it looks like you have some algae in there. Rez change and disinfect, h202 if you're running sterile. Add more airstones or increase pump pressure to get more oxygen into your solution.

CK

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I run a 1300 GPH air pump with 3 4x2 inch large airstones. Bubbles are on the entire surface of the water. There is 20 gallons of water in the reservoir.

1: The tote box is black body with stupid yellow lid. I have the reflective insulation as you can see to help darken inside but it's quite bright with lid closed, certainly not pitch black. Should I consider spray painting the lid to darken the environment? I've heard spray painting these plastic totes is tricky.

2: All the lower leaves of each plant is turning bright yellow and leaves are drooping.

3: I give them root guard. I know you do 1/4 nutes from first feeding and work it up slowly. I've also been given them 1/4 the rootguard dose. Should I go 1:1 with the Rootguard?

4: The DWC system has a water pump that feeds water to a distribution hub then to each net pot. The plants are in rapid rooters and the water feed comes right to the base of the rapid rooters. The water pump runs 24/7 and the rapid rooters are extremely saturated with water. Are the plants drowning? Im doing this top feed "drip" (more like stream) because I read it in a DWC setup guide on growweedeasy.

Thank you so much for taking the time to share your skillful input!

I run my top feed for 30 minutes, then off 90 mins throughout. The drip shouldnt be right at the base, move it so it is near but not right on it.

I've only used h202 to as an additive to fight rez funk but light, heat and oxygen are important. I'm even switching to black airlines because I have a bit of funk. Regarding your lid, possible that light is making it through the light colored plastic. Test it by holdingnit upto the light, then you can look into ways to block it.

Also, whatsbyour rez temps look like? Are you seeing big changes in ppm/ph? I take daily samples and test/record. That data can tell you alot about whats going on in your rez

CK

FruityHigh said:

Humidity is still not raising despite the humidifer on 24/7 and plants are beginning to get more yellow. This is very concerning and I'm not sure what to do.

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Why do you believe that the low humidity and the plant yellowing are related?

Nutes, ppm, pH? Turn your air pump down a little see if the plants respond

captiankush said:

I run my top feed for 30 minutes, then off 90 mins throughout. The drip shouldnt be right at the base, move it so it is near but not right on it.

I've only used h202 to as an additive to fight rez funk but light, heat and oxygen are important. I'm even switching to black airlines because I have a bit of funk. Regarding your lid, possible that light is making it through the light colored plastic. Test it by holdingnit upto the light, then you can look into ways to block it.

Also, whatsbyour rez temps look like? Are you seeing big changes in ppm/ph? I take daily samples and test/record. That data can tell you alot about whats going on in your rez

CK

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Should I buy a timer for my water pump? I'm really worried that these problems might be the result of "over watering" ie they're being suffocated to death with water in the rapid rooters.

Should I increase the dose of Root Guard? I currently give them 1/4 the recommended dose.

I actually put my phone in the res with lid closed a few days ago and its quite bright in there. Really, really bright. I wish I could find a manufactured black lid for the tote I'm using. As for temperature, I can't say for certain because I don't have a way to measure water temp (no temp probes), but the water feels cool.

I only found out some days ago to record pH daily. The first day I did that, two days ago, it was at 7 so I corrected it down to 6 (after the fact I learned that corrections should be slow and gentle... hindsight is 20/20...). I'm checking it every day now and now that if pH rises = plants need a bit more nutes next time and vice versa.

Beachwalker said:

Why do you believe that the low humidity and the plant yellowing are related?

Nutes, ppm, pH? Turn your air pump down a little see if the plants respond

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I don't know because I read somewhere that ideal veging humidity is nearly 60% and I'm all the way down in the low 30s. At this point is it a waste to have the humidifer running in the tent because it's not doing anything? I'm also worried about running the humidifier outside the tent in the basement (possible it could breed mold?)

Nutes are 1/4 recommended dosages
PPM unknown
pH was 7 2 days ago, 6 tonight

Yes, definitely get a timer for your feed pump. Im guessing that is the main issue. Secondary to that is the possibility of light getting through the lid. Oh, and just to put your mind at ease, its definitely not due to low humidity. My area averages 30% most days and Im good.

Lets start with getting a timer.

CK

captiankush said:

Yes, definitely get a timer for your feed pump. Im guessing that is the main issue. Secondary to that is the possibility of light getting through the lid. Oh, and just to put your mind at ease, its definitely not due to low humidity. My area averages 30% most days and Im good.

Lets start with getting a timer.

CK

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I tried liking your post. Great help!

No worries, you're welcome, I want your girls survive as much as I want my own to.

Everyone deserves to grow and enjoy their own. Glad I could help.

CK

I don't usually respond to small hokey hobbyist grows but I'm bored this morning and I see you have a little time and money invested in your set up.. I like your tent and light but I don't like your hydro system. I don't even understand it lol. If those plants actually start growing they are going to outgrow that tub set up very quickly. You would have to start them in flower like next week. If you had a simple ebb and flow system like the old Megagarden (or home made version) your plants would be loving it and it would be so simple.

You have TONS of bubbles. All those plants really need is for the roots to hang down in the res with lots of air bubbles. I would set the water level 2" below the net cups. I have no idea what a water pump is for. I do DWC in 5 gal buckets. I only use name brand nutes that other people have success with, with no other stuff like hydroguard, rootguard etc. No need for it if you can keep your root zone cool. If that isn't possible then I may not be much help.

You're going to need some kind of ppm meter. This is as cheap as any and seem to work fine for me.

https://www.ebay.com/itm/US-Digital...e=STRK:MEBIDX:IT&_trksid=p2060353.m1438.l2649

If you have some normal nutes in the 4-500 ppm range in a normal 5-6 ph range, the plants should be happy and grow nice and healthy. I don't see the algae but that would be bad yet easy to eliminate. I think more tin foil over the top would do it or some nice panda plastic film. I don't think temp and humidity are your problem. If those roots hit the rez with some moderate nutes in the right range they should take off. A lot of people have success with GH Lucas formula, GH Floranova, Dyna Gow, Megacrop, Jack's/Peters, and many others, take your pick.

If it was me, I would put 4 of them in 5 gal buckets with air stones and grow 4 nice bushes in that tent. With individual buckets you can even do some side by side testing with different nutes/nute strength. Best of luck dude.