Hi Calvin
Suggestion if I may? If you have fungus problems what about simply adding air for now? See how that goes first? A warm steam humidifyer is best. As you have found watering trays are not effective enough. I've tried this for rootless orchids. Too far North with too much winter heat to be effective. Its the same as a humidity tray. You just can't get enough water in 1 place for it to make a dent in the RH. You would need a pond

Clara

I used a fan (larger than a computer fan, tho) aimed directly at a pan of water for a few weeks in my light room. Even tho the room was not sealed, that raised the humidity about 10 degrees, in a room (about 12 x 16') where it is very hard to do that for more than a short period of time.

However, the pans feel kind of slimy even when they and the water look "clean", and I quickly grew tired of washing them every day, so I decided it wasn't worth it. I don't like raising colonies of bacteria and blowing them all over.

Maybe you could try it out first with stuff you have on hand before investing any money in it, just in case.

BTW, I love the warm steam vaporizers. They put out a lovely soft warm mist. And they're cheap, so if one breaks it's not a big deal. Not sure what they add to the humidity in a big room or open area. As Clara says, once the heat goes on it's hard to maintain any humidity at all. Especially in big spaces.

When I grew under lights, I had pans with water with a big fan sweeping back and forth across the area. It does raise the humidity about 10% in the immediate area of the plants.

To eliminate the nasty water problem, I put Physan in the water and it stayed sparkling clean. It was death to ladybugs when they fell in, but the trays stayed clean. Also adding hot water to the trays when refilling raised it by 15% but that was only effective until the water cooled off.

Brooke

I do happen to have a steam humidifier, so that's good. My issue last year was that the steam just kind of went upwards and dispersed, instead of actually reaching the plants. Since I'm growing on a three tiered stand, I'll have some trouble getting the steam to all three levels. I'll do some brainstorming though! Thanks for the suggestions!

If you have fungus problems you don't have to worry about humidity.

The best way I have found to raise humidity, outside of a fogger, is to take a cool mist humidifier and make large cut outs in the top cover to let the mist out. It may help to put a small fan over top of that to pull the mist away. It will run through water very quickly, but what most people do not associate is the evaporation rate in the pebble trays etc with humidity. If you want real humidity you have to have real water loss. Another good method is to place a white sheet behind the plants and soak that down daily.

Be wary of your humidity measurements. I have found that humidity increases in the grow room by 10-15% for two or three days after watering the plants.

What about using an ionic fogger to raise humidity right among your plants? They tend to be small, I think. I have not used one myself, but they seem like a good option, and you can set them on a timer. One person I know claimed that they created a white residue that would settle on things, but I think he was exaggerating a little bit.

Thanks for the tip about using physan to keep the water clean, Brooke.

I think I'll try again. Might also use it in the drip trays next time I wash them.

Water weighs 8lbs. per gallon. Most small vaporizers (hot mist) have a one or one and one half gallon tank and have no trouble at all putting that quantity of water into an average room in several hours. It takes several gallons of water in the average ~2000cu/ft room to make any appreciable dent in the RH and any method of humidity modification that does not move gallons of water from a water vessel isn't worth the trouble. One very low tech but effective method of humidity modification is your stove and a large stock pot. Fans blowing across water might be more effective than that same pan of water just sitting there but if that could work well there wouldn't have been a need to invent pleated paper wicks for cool vapor humidifier systems. Finally, water vapor is invisible. The output generated by an ultrasonic, hot mist or spinning disk humidifier while visible is not the actual humidity. Given enough time a large room can be humidified by a properly rated humidifier even though its mist only travels a few feet from the nozzle.

H

Hi Calvin. I don't know whether your setup is in a small room or a large open space. If it's the latter, my guess is that blowing air over pans of water towards orchids in an otherwise dry room will not mimic the generally humid atmosphere that is thought to be beneficial to plants. However, if adding fans is a GIVEN, then having them blow over pans of water may at least decrease the drying affect of otherwise unhumidifed air circulating around your plants. So then at least you would get more benefit from air circulation, if not humidity per se.

P.S. Howard I'm going to try your idea. I've thought about it many times, and it always seemed to make sense - knowing how humid a kitchen can become just boiling water for pasta. If putting it on a large burner on low is to much I can always try a small one. Wonder how expensive it will be to keep a burner on low every day. Not to mention the wear and tear on the stove. Still, I hate humidifiers - easier to wash a pot.

J

calvin_orchidlover

To add humidity I went to the local Goodwill store and bought several cool air humidifiers that are like little swamp-coolers. They cost less than $8 each. They work great and 2 are automatic.

treehaus MN

He isn't exaggerating. They do leave a white powder on everything including TV screens and PC monitors. I have a 2g Reli-On and it's the pits. It was $30 at Wal*Mart. I now use the small, room size type that are like mini swamp-coolers. I got them at Goodwill for under $8 each. Two are automatic and one is manual. I have one in the sun-plant room and 2 out in the larger GH.

hello, Howard and J, would using a crockpot be as effective as a pot on the stove? at least that can be left on all day unattended.
sue

All the ideas stated about raising humidity are good, but it all depends on what kind of heating system you have in your home - forced air, hot water, electric? I have hot water heat (radiators) and don't have to use any kind of extra humidity device. It just doesn't dry the air like a forced air system. If you do have forced air, I think it will be difficult since the whole principle of the system is a continuous supply of heated (usually dry) air pumped into a room. The cold air in the room flows back out (along with most of the humidity) via a cold air vent or return. I know some people attach humidity devices directly to their furnaces with this kind of system.

I really love my hot water heat. The few times I did use a humidifier to raise the humidity in my orchid room, I would only leave it on for a couple of hours and the humidity would go up to 70+% and stay there for most of the day. I then realized I was getting mold on some of my outside walls and stopped using it altogether. Even without it running, I'm still seeing my humidity levels at 55-60% right now.

Kevin

Kevin, I don't know what type of hot-water heat you have, but I have it and my humidity runs around 15% all winter with the heat on. I've gone the humidifier, vaporizer route and gave up. What I find works the best is keeping the plants close together in a large group. It forms a micro-climate and you get some rise (a few degrees) in humidity at around pot level.

I have oil heat with hot water baseboards. You must have something different.

Jane

I'm still pining after a humidifier I had in college (back in the dark ages). It was a rectangular tub that had to be filled with a hose - too heavy to carry back and forth. I didn't mind. It had a lift-off vented top and the works were simply a large partially submerged cylindrical sponge wrapped around a simple fan that sucked air through the damp sponge and blew it out into the room. It was quiet (emitting a very peaceful low whirring sound), no white dust, low maintenance and very effective. The air always felt fresh and buoyant. I loved it for myself, forget the plants. It was a Hankscraft.

I am trying the stockpot on low. Unfortunately, the room gets so warm with the stove and HID lights combined that even with a setting one notch above "low" RH stays closer to 45% than 50%.

John

Kevin, as a fellow Minnesotan I would be interested to know whether or not you cover your windows with plastic. I have steam heat, rather than water. It's nice not to have blowing air. I did not have a hygrometer last winter, but I have one this winter. Currently I have been seeing steady 55-70%, but I expect that to begin dwindling as temps drop.

Mike

Jane - That is odd. I have a very old house, so my heat comes from the big, cast iron radiators, but it's really the same principle as what you have. The only other reasons I can think of to explain your low humidity would be:

Lots of air loss in your house
Lots of big windows where humidity would condense into water
You keep your temps warm. Warm air escapes faster from a house than cooler air and carries the humidity with it.

Maybe there are other reasons, but I can't think of any.
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Mike

Sure do! Those 3M kits are the slickest invention since duct tape and boy do they make a difference. I still haven't turned on my heat this season. Right now my orchid room is 75 F with 55% humidity. The sun heats up the rooms nicely on the south side of the house. The rest of the house is 63 F with 61% humidity.

Kevin

Kevin, you are right. Large windows, not insulated and the heat keeps blasting trying to warm the room. Zero humidity.

John, I had one of those big humidifiers years ago also. Mine had wheels and I'd push it to the sink and attach a hose. Monster machine, but it worked. Had a big wheel inside with some sort of fiber which soaked the water while the fan blew on it. As I recall it wasn't expensive either. Don't make them anymore.

Low humidity isn't as important as most people think. My plants come through winter in pretty good shape. Light and temperature play the biggest role.

Jane

Jane, you're right. I used to have nightmares about my fogger breaking down and my parched orchids struggling to survive under my HID light. Not nearly that bad. Gosh, all those years struggling with that noisy troublesome machine.

Still, since even I'm more comfortable with a decent level of humidity, I imagine the plants are less stressed as well, so I do what I can to keep a good balance. The title of this post says it all. Air movement and humidity should never be discussed separately. They're paired, like the light and temperature that you mentioned.

J

aerides z6

I still have a small ancient Hankscraft "water breaker" type humidifier that's been in use since Noah's day. I needed more so went to the local Goodwill store and bought several different types of humidifiers, all for under $8 each. The water-breaker type add more humidity than the "swamp cooler" type, and faster. But the water-breaker type are harder to find. Only the electronic room mister puts a white powder in everything. I would never buy another one of those. But at the time it was all I could find in the local stores.

Well this has been a revelation. I've been reading posts about "swamp coolers" here for years. never realizing that I used to OWN one!

And now there's a slew of new and improved models (which I never would have found). This also explains why none of the humidifiers I bought duplicated that wonderful fresh buoyant atmostphere I remembered. The question is now, do I buy one for ME!

Thanks, greenhouser!

John

awesome replies everyone. As clara mentioned yeah I'm primarily trying to work out air movement actually. I just thought this was neat since I would get humidity in with the package. Plus, since I don't get to care for my plants daily (I go home 1-2 times a week) the increased dryness wouldn't be too good. Despite the low humidity, I don't really get any serious problems, so I'm more worried about air movement. I'm going to buy some computer fans - anyone have experience hooking those up to wall sockets?

I do plan on making a little aquarium type thing for my coelogyne nitida in my unheated cold room. I'll have a CFL and a fan hooked up. greenhouser (and anyone else who knows): What are these swamp cooler things exactly? I've googled them but I only see huge units. That 8$ deal sounds really good...are there miniature ones out there? Any links?

Thanks!
-Calvin