Reptile & Amphibian Forums

I have been racking my poor brain trying to increase the humidity in my AP cages. Last week, I think I discovered the problem...my hygrometer. It's a digital combo that reads temp and humidity with a single probe.

I started getting suspicious and decided to test it a bit. In my Burm cage, the temp is 86 on the hot side, but the humidity is only 37%. I just can't believe the humidity is so low. There's condensation on the walls and the doors, but on the cool side. That also happens to be where he wets, so I didn't think much of that. If I mist the cage, condensation forms on both doors. Same deal with the boa cage which sits on top.

Well, I checked the humidity outside last Fri and it said 59-62%. Here in Fl, Central FL at that, in the summer, that's not very likely. I'm a cracker and I happen to know that the humidity runs 70-80% most days in the summer. We got our afternoon thunderstorm that same day and I stood under a covered awning with the thing in my hand, during the rain, 100% humidity, and the darn thing reads 70%.

So, I'm looking at two situations: 1) my hygrometer is off. 2) my humidity is really low and the condensation is from the inside humidity cooling against the windows and walls of the glass (walls of the cage are cooler than ambient air inside the cage), making me think the humidity is higher than it is.

I would love to hear what you guys think about this. I've already closed off a few of the vents on the AP cages to increase humidity.

HA!
I have a similar problem... bought a 30$ digital dual temp/humidity reader....

it supposed to be totally waterproof--- after i noticed it acting funny- i put it IN water... reads 69% ... IN the water...

have tested it like you did as well-- put it outside in the rain... reads around 80%...

I think you're pleanty humid with condensation on the walls and doors... but thats just me...

~Beth
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The rescue site: www.freewebs.com/okreptilerescue

I posted in here early this year about a humidity problem. For AP cages I never have had a problem with just a water dish. My burm did fine and kept her on paper. In fact I keep my boa in there now. I had to change to aspen and I hate cleaning that stuff. I like it when its just a poop or pee but when I have to replace the whole thing, I hate it, and it always gets all over. I am thinking of changing back to kraft paper.

I digress, Kelly H posted what he uses to guage humidity, and it cost like 150 bucks or so, but I figure it is worth it if you have a big sized collection, and then there are people who do not worry about it and their snakes are fine.
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0.2 Rotts
1.0 Super Tiger
1.0 Amel Retic
0.1 Ball Python
0.1 Red Tail
0.1 Blood Python
1.0 Green Ananconda
1.0 Emerald Tree Boa

Hi Laura!
Sounds like your hygrometer could be off a bit but there are some things I'd like to point out.

First - I use a digital indoor/outdoor thermometer w/hygrometer made by Acu Rite (spelling?) that I get from Wal-Mart for about $13. It has about a 6ft wire probe, not the one with a wireless probe (they're a bit more expensive & I've never tried 'em). I've got several that I use and I've found them to be pretty accurate. They don't seem to last me much more than a year or so but for the price & accuracy I'm not complaining a bit.

When you stepped out on the covered porch during the rain your hygrometer was measuring the air it was in, not the air that it was raining in. However, I think it should've read higher than it did. At least 80% or more, unless there was a heat source nearby drying that air out.

Condensation inside a cage can help determine relative humidity by calculating the dew point. The temperature surrounding the outside of the cage, internal cage temperature and the humidity level within the area of condensation are all factors. It's not a way to get the exact humidity but you can get a decent ballpark figure. Here's the link to a dew point chart, in C & F, that might help. I don't for sure how accurate this chart is but maybe it can help figure out what's going on.
www.lamtec.com/dew-point-calculator.htm

"I'm a cracker..."

LOL!!! I wonder how many people have scratched their heads wonderin' what the heck you meant by that. Hahahaha!!! Pretty much only us "FL" crackers know what you're talkin' about. Hahaha!!!

Run to Wally's & get you one of the therms I menitioned. Mount the unit on the cool end (the unit itself reads humidity, not the probe end) and run the probe to the hot side. I use 2-inch boxing tape to tape the unit to the lower part of the wall so it measures the temp/humidity at the snake's level & I can easily read it.

Later Tater!
Mike
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Due to political correctness run amuck,
this ol' hillbilly is now referred to as an:
Appalachian American

www.natures-signature.com

HH said "Condensation inside a cage can help determine relative humidity by calculating the dew point. The temperature surrounding the outside of the cage, internal cage temperature and the humidity level within the area of condensation are all factors"

Man you sound like you went to MIT.
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0.2 Rotts
1.0 Super Tiger
1.0 Amel Retic
0.1 Ball Python
0.1 Red Tail
0.1 Blood Python
1.0 Green Ananconda
1.0 Emerald Tree Boa

"Man you sound like you went to MIT"

I did. Mentally Insufficient Technological school. Got any ink blots you need interpreted?
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Due to political correctness run amuck,
this ol' hillbilly is now referred to as an:
Appalachian American

www.natures-signature.com

"Run to Wally's & get you one of the therms I mentioned. Mount the unit on the cool end (the unit itself reads humidity, not the probe end) and run the probe to the hot side. I use 2-inch boxing tape to tape the unit to the lower part of the wall so it measures the temp/humidity at the snake's level & I can easily read it."

As my kids would say..."Well, there's your problem!" That's the model I have and I thought the probe measured the humidity. So I'm sticking the probe in the cage and the unit is in the outside living room air. I think I should have a permanent handmark on my forehead by now! Skip the math, I've been tutoring my daughter in Alg I Honors lately and that's enough. Ok, I'll stick the whole thing in the cage and see what's up.

Laura,
You have found what I believe to be the most common reason for people thinking they have lower or higher cage humidity than they really do. Low cost hygrometers are notoriously inaccurate and many can easily be off by 10% to 25% depending on the brand. Unless you are willing to spend 150 to 200 dollars for a NIST traceable with a certificate, you can never be sure if your hygrometer is reading accurately. However, you can test your own quite easily to see if it is reading properly, and here is the procedure:

1. Place a teaspoon of salt in a bottle cap or small cup and dampen it with a few drops of water (without dissolving it) to make it the consistency of wet sand.

2. Carefully place the wet salt and the hygrometer, or its probe if that type, inside a see-through container and close tightly. Don't allow any of the salt to directly contact the hygrometer. You can use a zip lock bag provided it seals good and you leave as much air as possible inside as well, or a plastic food storage container as long as it seals airtight. It may be better with the probe types to place the entire unit, probe and all, within the container so as to insure that everything is air tight.

3. Let it sit for at least 8 hours at room temperature and note the reading on the hygrometer without opening the container. It should read 75%, and the difference is how much your hygrometer is off.

4. If it does have an adjustment screw or other adjustment device, adjust to 75%, through a small hole made in the bag if necessary.

I have an expensive certified dial hygrometer I purchased many years ago and have checked it periodically using this method, and it shows to be a very accurate way to check hygrometers as when done correctly, the humidity within the container or bag is always within a percent or two of 75%.

Mike is correct in his dew point analysis, however the difficulty with that method is determining the exact temperature at which the condensation begins to occur. I would be curious as to the reading of your hygrometer when checked with the above method. When done correctly, it is extremely accurate and foolproof.

Kelly

nm