Somthings really wrong..

[kentosaurs]

Hi guys.......Well i placed a tray in my terrarium and i manage to get humidity up to the high 80's but something is seriously wrong here.....Whenever i start cooling down the terrarium with ice bottles the humidity immediately drops a lot.......Sooo what "science" am i missing here What does cooling have to do with reducing humidity....At first i thought maybe its just a coincidence that the humidity drop the time i placed the bottle in but then i tried it out a few times and SAME results!!!! Once it even when as low as the 30's

Heres a picture when there is no ice bottles


With ice bottles..Sorry for this blur pic...Anyways the it shows the humidity is 55%


Please help....

[bactrus]

Is there condensate on the bottle. Lots of it and the lid of your terrarium is only partially open (mostly closed)? Why not leave the bottle there till all the ice melts and at the same time note the humidity every 5 minutes. See whether the humidity drops when the bottle has condensate and after all the ice melts hence very little or no condensate whether the humidity picks up.

[kentosaurs]

Hi bactrus..condensate you mean by droplets of water on the bottle right?? And yes there is droplets...I shut the terr fully tight to try to keep humidity...I don't really get some of the stuff like

Why not leave the bottle there till all the ice melts and at the same time note the humidity every 5 minutes. See whether the humidity drops when the bottle has condensate and after all the ice melts hence very little or no condensate whether the humidity picks up.

[bactrus]

1. Take a couple of readings with terrarium closed before placing ice.
2. Take a reading outside terrarium also as control.
3. Insert ice bottle then shut the terrarium.
4. Take reading every 5 minutes till ice melts and water returns to room tempreture.

My two cents worth.

[kentosaurs]

Hi...

1.take readings while terrarium is closed without bottles = Done/humidity 80+%
2.take outside terrarium= Done/humidity 50-60


I was thinking could it be that since the cover was closed and i opened it to place the ice bottles in the humidity that was traped inside was lost???? But then again if humidity does go lower it should come back up after awhile since i shut the terrarium again... BA It takes a couple of hours before the whole ice bottle turns water and becomes room temperature LOL.....Anyways i'll try..

[kentosaurs]

This afternoon i tried putting in 1 ice bottle and from 80+ humidity it went down to 50+ (usual thingy) So after 6 hours im back from school and humidity was around 60's and the bottle has melted and tuurned room temperature...I took it out and cover the terrarium again and humidity went up to 80+ in about 10 mins.....Whats wrong!! LOL......Could it be that the cold temp affects my hygrometer??????

[arvin555]

Hey Nice, you have found it out yourself, I didn't know this too but I did some googling and found the following information from this site: http://archive.amol.org.au/recollect...f/humidity.pdf.


"Relative humidity is a measure of the amount of water-vapour contained in air at a
particular temperature. It is basically a comparison between:
•the amount of water-vapour held in the air at any one time and at a particular temperature; and
•the total amount of water-vapour which the air can hold at the same temperature, that is,
the amount of water which will saturate the air at that temperature.

Relative humidity is expressed as a percentage.
This can be written as an equation:
RH = water-vapour present in the air x 100%
water-vapour required to saturate air at that temperature
As the temperature of air increases, its capacity to contain water-vapour increases. For example:

•At 0ºC the air can hold about 6 grams of waterfor each cubic metre of air, that is, 6g/m
•At 10ºC this increases to 10g/m3
•At 20ºC it increases to 17g/m3
•And at 30ºC it increases to 30g/m3

So, if air at 20ºC contains 8.5g/m3
of water-vapour:
RH = 8.5 x100%
17= 50% "

So there you go, the answer is that the RH has changed when you cooled the air because the temperature went down and so the water holding capacity of cold air went down!

Where did it go? My guess is that the excess water that the air can't hold has pricipitated into dew (water droplets).

Now we know and knowing is half the battle! I'm glad that you made me check it out.

[jk]

Arvin, Extending your example, if the air at 20 degrees C. with 8.5 g./m3 were cooled to 10 degrees C., RH would increase from 50%, as you calculate, to 8.5 x 100% / 10 g./m3 = 85%. That's assuming that the air holds the same amount of water. Some water must be coming out of the air when cooled for RH to drop.

[caseyhoo]

Ken, I think you fill up yours terrarium with water. Full or half cover the terrarium. And try it. I believe the huminity will be better. Just 2cent. (reply yours thread with rush and didnt read what others reply.)

[kentosaurs]

Hi Arvin/jk

Thanks for the reply....Though i might not understand some of it but does this mean basically when the temperature goes down the amount of water the air can hold drops? And if so how do i actually bring humidity up but still maintaining the temperature

Casey

I have a tray in the terrarium already but does this mean i have to add more???



One thing..So how does highland plant get high humidity at night (in the wild) Mist??