1st grow box problem; HELP!

[mass]

So the first problem with the box is controlling the humidity. I have the timer on the humidifier set to go every 2 hours for 15min. It raises the humidity to 80% during that time span, but then it tinkers off to 30% before it's time for it to kick back on. If I set the timer too often, I'll be going through gallons of water every day.
How can I better control the humidity in there? And will the humidity jumping up and down like that send the plants into shock?

 

[adnedarn]

I was wondering how that was going to work for you.... I used that same humidifier in my first (small) greenhouse... Can you make it turn on more often for less time? You just need to play with the on/off time to get it to work. My main greenhouse is humidified by a cycle timer, it has different on/off times for day and night and requires frequent modifications to keep up with the weather (depending on how much the cooler has to run)
Andrew

 

[mass]

I was wondering how that was going to work for you.... I used that same humidifier in my first (small) greenhouse... Can you make it turn on more often for less time? You just need to play with the on/off time to get it to work. My main greenhouse is humidified by a cycle timer, it has different on/off times for day and night and requires frequent modifications to keep up with the weather (depending on how much the cooler has to run)
Andrew

Well, the timer I have it on now works in 15min. increments. So it is either on for 15min.+ or off for however long. I do have a different type of timer, but I'm not sure what length of time each little notch represents. So I didn't want to use it. But, maybe I can leave the humidifier on for 30min., every other hour.
Also, I have started keeping a record of the temp, humidity on each side of the box (left and right), and the time checked. Thus far, I'm losing 40% of my humidity after 1hour of off time. And by the end of the 2nd hour just before the humidifier kicks back on, it bottoms off at 35%-40% humidity in the box.
But my original question still stands.. Will the rise and fall of the humidity like this shock my plants?

 

[amphirion]

luckily, you have some pretty hardy plants. ventrata can take tons of damage (although i dont encourage purposefully doing so).

if you can't control the overall humidity of the entire area, try to localize it, i would do this temporarily by placing clear plastic cups over the pots and cover the plants. (spray some dH2O into the cup before placing it on top). this isn't a permanent fix, but it will do for the duration of time when you need to get your humidity schedule down.

 

[mass]

I think I may have it pretty stable now. I've got the humidifier kicking on for 15min. every hour. And I moved it to the center of the box with a custom cap on it so it distributes the fog evenly throughout the box. The night time temp is about 70deg. with 70% humidity. If my calculations are correct, then the daytime temp is going to be 80-82deg. with 75%-80% humidity. I'll know for sure tomorrow.
And the humidifier is pretty handy.. when the fog settles it keeps the substrate nice and moist.

 

[swords]

If you wish to truly "control" the humidity the enclosure should be close to sealed. If the shelf is wood that will suck up all your humidity very quickly.

A humidistat is the best option, unfortunately they run about $80 from these folks:

http://www.littlegreenhouse.com/accessory/controls2.shtml#humidistat

Look for the "prewired humidistat", hang the sensor in your terrarium, plug your humidifier into it and plug the humidistat into the wall. Done.

 

[mass]

I guess all I had to do was let it run for a little while. The humidity has finally leveled out between 70%-80%. So I'm back to having it come on every other hour.

 

[robthered]

I got me a hygrotherm and repti fogger for my terrarium. Works like a charm. The Hygrotherm is a humidstat/thermostat in one, it turns on foggers/humidifiers and heat mats/fans/cooling devinces when needed. Here's a link

http://www.petsandponds.com/en/reptile-supplies/c219173/p17106069.html

I personally like it a lot, no worries about the humidity dropping when I;m not home. Plus it has a photocell built into it which allows you to program a nighttime temperature drop.

Next thing I'm getting is a peltier machine.