I’ve seen it mentioned here that a sieve full of coarse salt on top of a bucket should be excellent for lowering humidity in a passive cheap way.
Never tried it, and not sure if it was a sieve or cloth or some other setup.
Does anyone else remember?
Edit: found it.
To make a rock salt dehumidifier, you’ll need a large bag of rock salt (also sometimes referred to as sodium chloride) and two 5-gallon buckets. You should be able to find both at a hardware store.
Drill several small holes in one of the buckets along the sides and the bottom.
Put the bucket with the holes inside the other bucket.
Fill the bucket all the way up to the top with rock salt.
Place the bucket in the area of your home you’d like to dehumidify.
The bucket will begin to collect water, and that water will drip through the holes of the inside bucket.
The water will then collect inside the outer bucket, trapping excess moisture.
Maybe Coco without HFF?
Or,I have a stock of canna terra pro plus,but Is not soil,It Is a soiless mix,can I use It with Maxibloom powder?
Should be less waterings too @George
If you have soilless mix supplies I would go definitely with hempy buckets, just fill once a week or so, there’s lot of info around and a lady here had great succes with them …
Seems a good Idea,but terra Is a mix of peats and coir, don’t know if It Is good for hempy,Coco does though.Can I still run It in Little buckets?Say 2 liters?With Maxibloom as a cheap fertilizer @George
Do you have height problem in your tent? The bigger the pot, the better, less watering , I also have humidity problems and use 3 gallon fabric pots to avoid it …
I have actually some room,but want to do a seed run this time,so with my rh being about 65% with 22-23C without any plant in the tent, I planned to do 2x1 liter Coco coir airpots,they are very Little, don’t know if It gonna splash so much humidity.The last grow was 3x 1gal pots and the plants were HUGE SHIT,needless to Say RH was about 70% and at times over
Anything over 60% RH is a call for mold , I had it in my last run only in some big buds, I plan to top and do mainlining, you need big plants to do that. You have to change for good, adapt to circumstances and plan only what you can bring to success, it takes time to find out what’s good but once you have the clues it’s just a routine you perfection grow after grow. Forget about little plants, bigger are easier to prune, trim and handle …
To address your original question regarding UVC bulbs for the purpose of sanitizing your grow room, I have and use UVC in between each grow.
These bulbs produce enough ozone gas to easily fill a tent or medium sized room. My space is a little under 200 sq ft feet.
The instructions with the bulb say that 15 minutes of exposure is adequate for that size room. I run it for 30 and then completely evacuate the room with a T8 fan spinning at 10. That Beast can clear the room in about three minutes and the duct vents to the outdoors through a dampered vent. I leave it running for half an hour. You can easily smell ozone so, run the fan till you can’t smell it.
You need to know going in that Ozone gas is pretty gnarly stuff. It attacks some rubber and plastic types and, apparently, all living things. Don’t look at the light, and don’t breath the ozone.
It is easy to avoid having any problems tho as long as you can dump all the ozonated air outdoors. Actual outdoors, not into the next room or whatever. If you can’t manage that UVC probably isn’t for you.
Used safely it ozone is the deadly enemy of your grow room pests including mold, fungus and most critters. Even spiders succumb and IMHO they are the hardest to kill.
I am also a recent convert to HCO hypochlorous, and there’s a spray bottle on hand. I sprayed a black mold spot on my cloning tray and the next day it was dead and crusty. Hospitals use foggers with HCO for disinfection so it should be safe for our purposes.
@GrouchyOldMan thank you so much.
I have 2 questions:
1 I do have a big Window(2-3 meters in h X1,5m in width.I can open the window,close the Door and run the lamp.Could It be enough to change the air?
2With that gas,Is It ok to run It even tho I have Pets in nearby rooms and other people ?
Oh I forgot,the room the tent Is in Is 25-30meters squared.Idk how It converts to feet.The box Is a Little bigger than 2x2x5.But my room Is full of spores for sure.
I’m not sure I’d risk it unless your tent itself has a fan that vents outdoors.
The close proximity of people and pets isn’t a problem as long as the tent with the light in it is relatively sealed. My room is in my basement but the ozone is mostly contained in the room. Ozone isn’t “Deadly” poison or anything it’s actually more corrosive than anything. Bad for lungs, etc.
I think you might be happier with the HCO spray down if you can find a source. If your wallet is fat, look for an electrical fogger and dose everything in sight with Hypochlorous!
So It must be applied in my room Just by spraying It or should I aim and spray at some surfaces or targets?Can’t rely on a fogger tho.
The UV light must be fixed in the tent or should I use It with my hand,passing It above the plant?I also would Need special glasses too.
Would It damage the plant?
I Just saw a 38 w lamp on Amazon that has a good square meters range,a proximity sensore and It Is UVC lamp,with a timer.Idk if It could be the easiest for me to run It in my room.But Have no duct for exhaust,Just my big window
Bad Idea, you do not want to be there when it is lit. Any cheap light fixture will work to hold the bulb. I have an overhead light socket, other’s use a desk lamp, or standalone reading lamp. You just run an extension cord outside the room and manually plug it in to start a cycle.
Seriously tho, you won’t want that ozone smell around long enough to use one window for ventilation. Doesn’t your tent have a fan and ducting you could lead out the window?
Also, all you need is the bulb. timer, proximity sensor: Overkill.
Sadly I cannot run a duct to the fan,It Is a hell of a job to get the window tent adapter and run a very long duct,my room Is big,also the fan would not be efficiente with this long ducting
Basically yes,It Is not suitable to use uvc at the Moment.I have to try to keep VPD values and lower humidity to try control the mold,also not having a single giant cola is a good strategy too @GrouchyOldMan
@Andrexl I used to use one of these. CleanLight Pro 36W.
I swept the light over the plants daily, and it did help keep White Powdery Mildew in check. It did not eliminate it.
The light needs to hit the mold directly in order to kill it, and it has to be pretty close to it. It’s really hard to get complete coverage on a big, bushy plant. At close range the light can damage leaves.
I did get some brownish mold that may have or may not have been botrytis, I’m used to seeing that as gray. I never did see any of that.
Eventually I did @JoeCrowe 's sulfur treatment, and have been pm free for 9 months. No other molds, either, but I’m not sure if sulfur is effective on budrot.
I’ll check out the hypochlorous if I ever see it again.
I don’t know about the GH silica but yeah probably it’s fine at the right dilution, it’ll say on the bottle if so. I don’t know where to source either of those exact products in Europe, but AgSil is just a commercial agriculture product, it’s soluble micronized potassium silicate, and there might be a comparable Continental product from some farm and garden company over there. Chitosan is pretty easy, either look for insect frass in organic gardening places, usually from black soldier flies, or find yourself some crab, lobster, or shrimp shell meals in the same place. In the US, those would be one of these products:
You can also gather those as food scraps, from friends or family or maybe from a fish market or restaurant if you have access to them. Then rinse them off and dry them thoroughly in a low oven, all the way through so like 120C for an few hours till crispy but not browned or anything. When they cool off, grind it into a coarse meal and you can put that right in your soil mix or top dress with it.
One source of silica that might be easy for you is to see if horsetail grows in your area and go find some and make an fermented tea with it, to foliar with or water in. Horsetail is one of those wild and crazy bioaccumulators with very deep tap roots and it has so much silica in it that’s released when you break down the cell walls with fermentation. This recipe doesn’t add anything to it, I’d probably add like a single tablespoon of brown sugar to the whole batch just to kick off the bacterial life in it.
If you are making seeds and there is bud rot on your buds, spraying the sulfur on there will stop the botrytis in it’s tracks. Sulfur is effective against most pathogenic fungus, except water molds.
What I recommend is a thorough cleaning of the grow room, and strict environmental controls to eliminate bud mold. Personally, I’ve never seen a UVC bulb that is as effective as a vacuum, mop and sanitizer.
, I also have humidity problems and use 3 gallon fabric pots to avoid it …
, I had it in my last run only in some big buds, I plan to top and do mainlining, you need big plants to do that. You have to change for good, adapt to circumstances and plan only what you can bring to success, it takes time to find out what’s good but once you have the clues it’s just a routine you perfection grow after grow. Forget about little plants, bigger are easier to prune, trim and handle … 
