Newbie custom fridge grow box

[Aqua Man]

The reason you are seeing a spike in humidity with the lights off is the temperature change. Ergo relative humidity. Find a way to keep temps similar and this spike will go away. Going to 24 hrs light will fix the issue but the funny part about that is the plants will actually transpire more. Giving off more water vapor but because the temp stays the same the humidity issue will be corrected. If you run the same day/night temps you will eliminate this all together. So using a heater during light off may be a good option.

I use a programmable controller for my heater and used to drop temps by 2f every 30 min at lights out to allow my dehuey to keep up as it was small. The controller is plug and play and costs like 40-50 US.

I now have a bigger dehuey so it's not an issue but thats the cheap way to do it in some cases it's just cheaper to control the temps if your lights on humidity is in a good range. A dehumidifier would be a good investment if you struggle with overall humidity issues. But if it's just night humidity temp adjustment is often a better option

 

[mantistoboggan]

Looking really good man, you seem to have everything dialed in really well for a first go! And also very innovative setup, back in the day I've used fridges, old computer towers, anything I could fit a light and an exhaust fan into, haha.

Awesome stuff, I'm following along.

 

[Fridgegrow]

A cheap temporary fix could be a baking pan or something larger surface area covered in a thick layer of baking soda, or some kind of breathable cloth bag full. Will help pull humidity from the air some.. I wouldnt expect miracles but it could at the very least help keep it within tolerable levels until you figure something better out or do get the money for AC/dehumidifier
Air movement is important in high humidity. I had this issue also for a while and using a big box fan on high gave enough movement to keep the humidity from building up on leaves until i got the AC running in the room

This is the thing, I've got the exhaust thru the wall to outside to prevent it dragging in warm air, and that didn't make much difference so I also put the intakes thru the wall so they're pulling in clean fresh air, and it still didn't make a difference, then I went on the met office app, and humidity round by me yesterday went upto 97%!
I know a dehumidifier would help but I just feel I keep throwing money at this thing so if I can fix it without spending any money I will, but if I can't keep it down I'll have no choice but to buy one.
I've had some very challenging weather to deal with over the last month hahaha, been a nightmare, But the old girl is still looking good, apart from I've noticed some brown, almost rust looking spots on only the top leaves, I've done some digging and looks like a calcium deficiency so I've bought some cal mag and will give it a try when it's ready for watering. Fingers crossed. Thanks so much for all the help guys it's much appreciated, the longer this grow goes on the more worried I'm getting about it all going Pete tong at the last minute.

 

[Fridgegrow]

The reason you are seeing a spike in humidity with the lights off is the temperature change. Ergo relative humidity. Find a way to keep temps similar and this spike will go away. Going to 24 hrs light will fix the issue but the funny part about that is the plants will actually transpire more. Giving off more water vapor but because the temp stays the same the humidity issue will be corrected. If you run the same day/night temps you will eliminate this all together. So using a heater during light off may be a good option.

I use a programmable controller for my heater and used to drop temps by 2f every 30 min at lights out to allow my dehuey to keep up as it was small. The controller is plug and play and costs like 40-50 US.

I now have a bigger dehuey so it's not an issue but thats the cheap way to do it in some cases it's just cheaper to control the temps if your lights on humidity is in a good range. A dehumidifier would be a good investment if you struggle with overall humidity issues. But if it's just night humidity temp adjustment is often a better option

Thanks for all your help, I thought having a small grow area it would be real easy to control, and it has been up until now, but having such drastic changes in the weather has proven to be a nightmare. I bought a new heater a couple of days ago which is much better, its on a thermostat so doesn't drop below 20°c when lights out but still doesn't help the humidity much, fans on full most of the time.

Ive got a few changes Ill make before I do another grow, but youve got to start somewhere and you definitely learn from your mistakes.

I'm gonna keep my fingers crossed that I can still pull a decent yield.

Thanks again for all your help it's invaluable.

 

[Fridgegrow]

It's only minor at the minute, am I right thinking it's a calcium problem do you think? Want to nip it in the bud early.

 

[mantistoboggan]

View attachment 985073

It's only minor at the minute, am I right thinking it's a calcium problem do you think? Want to nip it in the bud early.

Try to get a pic without colored lighting on it so we can see the true color of the leaf and the deficiency. seeing the exact color is invaluable when diagnosing issues. Some problems look like others under a blurple LED.

 

[AnselAdams]

Just a quick question guys, I'm really struggling with high humidity at the minute, the humidity outside has been over 80% everyday this week so far, and when the lights are off its 70% plus in there.

So will I do any damage to the plant if I switch from 18/6 to 24/0 at this stage?

I can keep the humidity around 40% with the lights on. I know a dehumidifier will fix the problem but I'm getting a bit fed up of spending money at the minute lol.

If this is an Auto then 24/7 light will not hurt it. My last three grows have been 24/7 from germ to harvest and my yields have been awesome! The same may not be true for everyone but for me; with this strain, 24/7 works.

My humidity is very consistent, i use AC Infinity T-4 and T-6 fans with humidity and temp sensor to control the environment. I use a pulse environment meter to keep an on on everything and to check/chart over time. The pulse meter has been a great help in helping me tweak my environment. I control each cabinet/tent as its own. Below is the chart for approx. a two day period.

Personally I would start by leaving the lights on 24/7 unless someone can explain why not. Then you will need to watch your leaf temps (obviously you are aware of this, you already raised the lights... lol). Remember actual leaf temp is just as important as the ambient room temp.; as it is the leaf temp that the plant uses to determine when and how much to "breath"/transpire.

With regards to your humidifier. Look for one where you can pre-set the percentage of humidity desired (they are not very accurate, close enough). That will help a lot.

Those two adjustments and monitor time should get you through the next week or so.... before you find something else to worry about. It is a never ending story; like children.

Happy Growing

 

[Fridgegrow]

Try to get a pic without colored lighting on it so we can see the true color of the leaf and the deficiency. seeing the exact color is invaluable when diagnosing issues. Some problems look like others under a blurple LED.

It only appears to be on the top and it's only affecting a few leaves, is it anything to worry about?

 

[Aqua Man]

View attachment 985381

It only appears to be on the top and it's only affecting a few leaves, is it anything to worry about?

I wouldn't worry to much if you have 2 more weeks to go but adding 1/4 cal mag to feed may help.

 

[pdasterly]

did same thing a few years back, using old pepsi display fridge.
toss a scrog in there

 

[Fridgegrow]

I have a increasingly sick plant guys :( I got some cal mag and after about 5 days still no better. I'd say about 60% of the leaves are like this now, although the buds still seem to be growing quite well.
I switched from 18/6 to 24/0 as I was struggling with humidity, would it be worth switching back to see if that does anything?

Extractor fan is on full constant and got great airflow, got a thermostatic heater set to 22°c.
I just can't understand it? Looks like some sort of fungal infection, I'm on week 6 now is it worth getting a fungal spray?

Temps are a consistant 26°c, humidity ranges from 45%-55%
Any ideas? Tia

 

[Aqua Man]

Those look like a lot more than 2 weeks away from harvest. What size container with what media and what have you been feeding it.

The

 

[Aqua Man]

Do you have a ph and ppm meter to check the runoff? Kinda thinking you have a low soil pH from nutrient buildup and that can affect calcium uptake

 

[Fridgegrow]

It's in a 5 gallon air pot, I've got a pH pen but I've only checked the water going in which is 6.4, I haven't checked the run off.

The humidity was getting high last week so I ended up getting a dehumidifier which has brought it down to a steady 45-55%.

It's really strange as it's only affecting some colas, there's other colas that look perfectly healthy.

I have cut a few of the lower leaves off that wernt getting any light and had started yellowing.

I'm using canna professional soil, and I have used canna flores nutes but only ever gave them 50% of what was recommended on the bottle, and Ive only gave them water for the last few days as I thought flushing it a bit might help.
It's so frustrating, I've tried so hard to keep it as perfect as possible,
What are your thoughts? Thanks

 

[Greenjourneyman]

Hey Fridge man,
don’t get frustrated, it’s all apart of the learning curve.
I like using these charts of course not every problem is simple and going to have an easy fix.
Ive noticed that when dramatic shifts occur something will go a little wrong, youve hadsome big swings in humidity. Just stay the course and make small changes then wait to see result.
Aqua man might have a point there about the calcium. I’ve had that discoloration with over feeding too.

 

[Aqua Man]

It's in a 5 gallon air pot, I've got a pH pen but I've only checked the water going in which is 6.4, I haven't checked the run off.

The humidity was getting high last week so I ended up getting a dehumidifier which has brought it down to a steady 45-55%.

It's really strange as it's only affecting some colas, there's other colas that look perfectly healthy.

I have cut a few of the lower leaves off that wernt getting any light and had started yellowing.

I'm using canna professional soil, and I have used canna flores nutes but only ever gave them 50% of what was recommended on the bottle, and Ive only gave them water for the last few days as I thought flushing it a bit might help.
It's so frustrating, I've tried so hard to keep it as perfect as possible,
What are your thoughts? Thanks

It's a bottom feed system right?

Is there a way to measure runoff?

 

[Aqua Man]

I don't think you have been over feeding I just think as water is being taken up some of the nutrients are left and over time they build up.

 

[Fridgegrow]

It's a bottom feed system right?

Is there a way to measure runoff?

No not a bottom feed system.
Ive cut some leaves of with a Stanley knife and I didn't steralise it beforehand, do you think that could be the source of the problem? Initially I thought it was the fan was too close, I moved it about 5 days ago but still no real improvement, it hasn't got any worse but hasn't got any better either.

 

[Aqua Man]

No not a bottom feed system.
Ive cut some leaves of with a Stanley knife and I didn't steralise it beforehand, do you think that could be the source of the problem? Initially I thought it was the fan was too close, I moved it about 5 days ago but still no real improvement, it hasn't got any worse but hasn't got any better either.

My bad was thinking autopot
Nah not likely.

When you water next catch the run off and measure it. If the nutrients are building up the ph should be a fair bit lower. This can affect calcium uptake. You have added cal mag and it's getting worse which tell me it's an availability issue.

 

[BogartAmungus]

If this is an Auto then 24/7 light will not hurt it. My last three grows have been 24/7 from germ to harvest and my yields have been awesome! The same may not be true for everyone but for me; with this strain, 24/7 works.

My humidity is very consistent, i use AC Infinity T-4 and T-6 fans with humidity and temp sensor to control the environment. I use a pulse environment meter to keep an on on everything and to check/chart over time. The pulse meter has been a great help in helping me tweak my environment. I control each cabinet/tent as its own. Below is the chart for approx. a two day period.

Personally I would start by leaving the lights on 24/7 unless someone can explain why not. Then you will need to watch your leaf temps (obviously you are aware of this, you already raised the lights... lol). Remember actual leaf temp is just as important as the ambient room temp.; as it is the leaf temp that the plant uses to determine when and how much to "breath"/transpire.

With regards to your humidifier. Look for one where you can pre-set the percentage of humidity desired (they are not very accurate, close enough). That will help a lot.

Those two adjustments and monitor time should get you through the next week or so.... before you find something else to worry about. It is a never ending story; like children.

Happy Growing

View attachment 985285

I know I have read it somewhere but what is the ideal leaf temperature range? Under LED's