Bud Rot and the conditions it's most likely to happen

[vyserage]

So i got hit with bud rot for the first time. I noticed it was getting below 60f in the house when the door is open so i started closing it. I ended up getting bud rot and it turns out the humidity was jumping up to 70% + with door closed (even when its raining outside). By having it cracked open i can keep humidity in the 55 to 65 max range but the temps are down to 62f, sometimes 58f.

My question is between those 2, whats more important? Keeping humidity down or temps down? I did add a second fan in my tent on opposite side to help avoid anymore rot and so far so good. I've been keeping door cracked to keep humidity down but for all i know rot is more likely to happen with below 65f temps.

 

[Old Salt]

Humidity is the rotter giving you problems.

My temperatures range from 18°C (64°F) to 32°C(90°F) humidity from 30% when lights are on, to 62% two hours after they go off. The humidity drops quickly after that to about 50%. I have a ceramic heater in the tent to ensure the minimum is 18°C (64°F), and a humidifier trying to keep the humidity above 35%.

Summer, with it's high temperatures and humidity gives me problems. The temperature rises to above 40°C (105°F) and the humidity rarely dropped below 75%. I lost about 1/3 of my crop last summer to bud rot. I may try a basement grow this coming summer.

 

[vyserage]

Summer, with it's high temperatures and humidity gives me problems. The temperature rises to above 40°C (105°F) and the humidity rarely dropped below 75%. I lost about 1/3 of my crop last summer to bud rot.

Thank you!! That means the factor is humidity i want to watch for! I was leaning more towards humidity too but because temps were getting so cold, that could have been a big factor too, so i wasnt sure.

 

[TurboBucket]

Yup as oldsalt mentioned it's the humidity that's getting you.

Temp and relative humidity are directly related. If you increase the temp you will increase the Rh provided you are not adding more moisture to the space (which plants do as they breathe).

More airflow will help, (mold spores like stagnant air) so the extra fan was a good call. A dehumidifier would be best but they aren't cheap. A small heater could be beneficial provided there's enough air vented from the space to match the transpiration of the plants.

Lower night time temps are a good thing and can help encourage coloration in some strains. I pretty regularly get temps down into the upper 50's with no I'll effects. Some strains can tolerate even lower.

 

[vyserage]

Yup as oldsalt mentioned it's the humidity that's getting you.

Temp and relative humidity are directly related. If you increase the temp you will increase the Rh provided you are not adding more moisture to the space (which plants do as they breathe).

More airflow will help, (mold spores like stagnant air) so the extra fan was a good call. A dehumidifier would be best but they aren't cheap. A small heater could be beneficial provided there's enough air vented from the space to match the transpiration of the plants.

Lower night time temps are a good thing and can help encourage coloration in some strains. I pretty regularly get temps down into the upper 50's with no I'll effects. Some strains can tolerate even lower.

Good to know, thanks!
I thought about putting a small heater in the tent but felt like because of the 4inch inline fan bringing in the cold air it wouldn't workout so great with the even colder air cominf in from the door being cracked open. The door being cracked open is a requirement if I don't want 71+ humidity.
When the lights on it's definitely a bit warmer. 11pm to 11am is my lights schedule.

 

[HigherTheHigh]

I suffer from the odd chance of bud rot but since i turned my fan up on a night it soon got rid of the 50-75% HM.

I also found that any leaf that touched another bud during the night it then caused it to have slight bud rot from the leaf displacing the smallest particles of water, i also found not watering ill the full 10% run of helped massively in flower, i think everyone can judge there own pot weight, when i had a camera up recording straight after i watered with the 5-10% run of the HM would spike as much as 70% with the lights on, i do water till run off in veg as you know yourself you cant cause no problems with high hm there, for flower i water till theres a slight drip.

What size carbon filter are you running to the size tent? iv got a friend that runs the same size tents as me and some times we will compare them he was running a 4x4 same as me but he was running a 6"300mm filter and i was running a 6"600mm long filter, we both ran exactly the same nutrients, lights everything, except that filter, his got bud rot in the last 2 weeks where my plants ripened without a problem.

I know its a lot to read but for someone who's had over 30-40 plants with bud rot iv narrowed my ways to doing it like above .

 

[vyserage]

I actually don't use any filter, just a 4 inch (maybe it's a 6 inch) inline fan sitting on the bottom intake opening. There is not another fan for out take, I let the positive pressure blow the air out.

 

[NuttyProfessor]

need fresh air in old air out 2 fans , , ........dehumidifier ( always good to have ) you can dry your buds with them also they are not to over priced these days i got a lovely one like new off ebay for £85 but there are smaller ones for half that price , but you will have to empty more

 

[HigherTheHigh]

Your best of getting a fan and taking the old stale air from the top of your canopy out, iv found the higher the HM the higher inside the tent, my veg room sits at 30-40% HM at pot level, 40-55 canopy level, then it can sometimes hit 55-60 near the lights so you could be possibly dragging all of your old air through your plants, try get a 4" extractor fan, it will lift all of the crappy air from the top of your plants and away, will save you on bud rot too.

 

[NuttyProfessor]

this is the little one i bought , its pretty good , has a clothes drying function i use when drying

 

[vyserage]

I do have a small dehumidifier but I don't see it being capable of handling all the humidity, especially for a 4x8 tent in the livingroom. The new air coming in would be too much for it to handle. How does that big one do for you?

 

[NavNurs]

What part of the light cycle are you at when you water them?

 

[vyserage]

What part of the light cycle are you at when you water them?

its a 7 bucket RDWC

 

[NamTran]

I notice that there's always condensation of leaves that are touching each other . So I reckon that having them touching buds would produce stagnant wet spots which appear to be the ideal condition for molds to settle.

P/S: dehumidifiers are nice but they are not cheap to run .

 

[NavNurs]

its a 7 bucket RDWC

GTG, I have zero experience with that set up. Is there any way to minimize evaporative loss into the tent? I’d think the less sq ft of exposure into that atmosphere the better you might be able to control ambient humidity.

Good luck! I lost an entire crop due to not picking up on it in time, and watering soil just before the lights went out. This time Ive avoided that mistake though the room is now seeded with spores. I’ve also also hit them with GreenCure’s fungicide during veg when they showed even the first signs of WPW. It is just potassium Bicarbonate and nontoxic, but that doesn’t mean I want to smoke it!

 

[oldsmokey]

If I only had one fan to run in my room it would definitely and be my exhaust fan. Any air you remove from the room will automatically be replaced and if your tent is sealed well most of it will be coming in from your fresh air intake. It's the way I run my room now will probably have to put a fan on the fresh air come summertime.