# Exo Terra Digital Thermo Hygrometer Combometer



## I'mNew2Frogs! (Jan 23, 2019)

What do you guys think about the Exo Terra Digital Thermo Hygrometer Combometer?

It looked like it was working fine but now I'm not sure. The temp looks right but the humidity is reading 99% and will not move off that number. I guess it could be 99% after misting, the glass all fogs up but as an experiment I did not mist last night and I left the doors to the viv open (I have NO frogs yet lol). Humidity level still at 99%

I pulled the battery before leaving for work today thinking maybe it will reset?

If that doesn't move the needle I'll pull the probe from the viv and put it in the garage. The reason I haven't tried this yet is that I have the probe behind the background and it's hard to get at.


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## Socratic Monologue (Apr 7, 2018)

If you have the probe behind the background, you won't be measuring the temp or humidity of the parts of the viv the frogs are living in (which is the purpose for the meter, I'd guess). 

Likely there's a very humid microclimate back there, or condensation back there soaked the probe, or it is simply a faulty unit (not all that uncommon).


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## I'mNew2Frogs! (Jan 23, 2019)

Socratic Monologue said:


> If you have the probe behind the background, you won't be measuring the temp or humidity of the parts of the viv the frogs are living in (which is the purpose for the meter, I'd guess).


The Exo Terra foam back has voids on the backside that line up with the holes in the top plastic lip of the viv for cords. I'm assuming that the void is for probes and running any other electrical cords/devises like heat cable?? That was my thinking anyway.

Maybe I'll run the probe out in the living area and see what happens.


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## Socratic Monologue (Apr 7, 2018)

Yes, I know the feature you're referring to. I'm not sure what the manufacturer had in mind, but putting a probe back there is not going to give you reliable readings at all: humidity is pretty localized according the ventilation in a viv. The foam background will insulate the heat from the viv, while the glass will conduct it from the room pretty well; a temp probe back there will likely read the ambient room temp more reliably than the viv temp.

I tear out those backgrounds and try to give them away, so I don't know first hand, but there are very mixed accounts here about the safety of those Exo Terra backgrounds in dart vivs -- styrofoam endocrine disruption, frogs getting stuck, foam breaking down... Might be worth some research since you're moving things around.



I'mNew2Frogs! said:


> The Exo Terra foam back has voids on the backside that line up with the holes in the top plastic lip of the viv for cords. I'm assuming that the void is for probes and running any other electrical cords/devises like heat cable?? That was my thinking anyway.
> 
> Maybe I'll run the probe out in the living area and see what happens.


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## Flip00u812 (May 19, 2015)

I had one that did basically the same thing except with mine the humidity readings stuck low. It’s not the best product I’ve used. I ended up removing mine after I got comfortable with how my tank was doing.


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## rhino43grr (Oct 2, 2011)

I have one that's also been reading 99% in the tank regardless of how long I go between misting. I took the probe out and blew on it and the humidity reading dropped, but when it's in the tank it goes back up. I'm going to try taking it out and leaving it outside the tank for a while to see if anything changes.


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## I'mNew2Frogs! (Jan 23, 2019)

rhino43grr said:


> I have one that's also been reading 99% in the tank regardless of how long I go between misting. I took the probe out and blew on it and the humidity reading dropped, but when it's in the tank it goes back up. I'm going to try taking it out and leaving it outside the tank for a while to see if anything changes.


I took the probe out from behind the foam back. Member here recommended that as did Josh's Frogs and even called Exo-Terra. All said behind the foam back wasn't the best idea.

Still reading 99% even though my plants this morning were looking a bit dry. The leaf litter still has a little, very little, water on them, spag moss is wet.

I left the doors open (no frogs yet) and the reading dropped. I took probe out and the reading dropped so can only assume it's not "stuck" on 99%

They recommended to keep the probe in the main living area but don;t get any water on the probe when misting...how the hell do you do that without removing the probe every time?


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## Socratic Monologue (Apr 7, 2018)

I'mNew2Frogs! said:


> They recommended to keep the probe in the main living area but don;t get any water on the probe when misting...how the hell do you do that without removing the probe every time?


I've seen people recommend that you put the probe under an inverted film canister stuck to the side of the viv. Still less than ideal, since the inside of the canister won't ventilate the same way as the rest of the viv.

I don't think a hygrometer is necessary, or even beneficial (what if the thing reads 99% but your plants are wilting and drying out? Are you going to believe the meter, or your plants?). 

Maybe put the probe in there for a week, and be careful not to get it wet, and watch how the humidity % fluctuates according to how the viv looks; then you'll know what 'too wet' looks like, and what 'too dry' looks like. Then put the meter away and keep things between 'too wet' and 'too dry' and watch your plants (and in the future, your animals).


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## I'mNew2Frogs! (Jan 23, 2019)

Socratic Monologue said:


> I've seen people recommend that you put the probe under an inverted film canister stuck to the side of the viv. Still less than ideal, since the inside of the canister won't ventilate the same way as the rest of the viv.
> 
> I don't think a hygrometer is necessary, or even beneficial (what if the thing reads 99% but your plants are wilting and drying out? Are you going to believe the meter, or your plants?).
> 
> Maybe put the probe in there for a week, and be careful not to get it wet, and watch how the humidity % fluctuates according to how the viv looks; then you'll know what 'too wet' looks like, and what 'too dry' looks like. Then put the meter away and keep things between 'too wet' and 'too dry' and watch your plants (and in the future, your animals).


I like all three of your points. I think the thermometer function will be far more useful to me than the hydrometer.


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## Socratic Monologue (Apr 7, 2018)

I'mNew2Frogs! said:


> I like all three of your points. I think the thermometer function will be far more useful to me than the hydrometer.


Thanks, I like them too! (Aw, shucks... )

Seriously, I have roughly the same advice for the thermometer -- given a certain lighting setup and a certain amount of ventilation, you should be able to figure out pretty quickly how many degrees above ambient your viv runs (likely it'll be something like +5F at the top and approximately ambient temp at the bottom, or a degree or so cooler from evaporative cooling). But if you like having a digital readout just for a periodic reality check, that's understandable too.

I guess, like with all technology: use it, but don't let it use you. If it frustrating you, smash it with a rock and get back to enjoying your project.


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## I'mNew2Frogs! (Jan 23, 2019)

Socratic Monologue said:


> I guess, like with all technology: use it, but don't let it use you. If it frustrating you, smash it with a rock and get back to enjoying your project.


Too funny but sound advice. LOL


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## TGross (Nov 16, 2018)

Yeah, I've got one of those too. Mine's always stuck at 99% humidity, so I completely ignore that number and just make sure that the glass of my viv is fogged up. I use it for the temperature function, since that seems to be at least fairly accurate, but I'm going to be upgrading to a more accurate thermometer that'll turn on my air conditioning unit once it gets too hot. Honestly, I'd recommend you do something similar and get a better thermometer (and hygrometer if you can).


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## I'mNew2Frogs! (Jan 23, 2019)

TGross said:


> I'm going to be upgrading to a more accurate thermometer that'll turn on my air conditioning unit once it gets too hot.


Would be very interested in what you come up with.


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## Old_Trekee (Dec 8, 2013)

For those digital hydrometers to work correctly, they must not get sprayed with water. I hang mine in front of the misters where they don't get misted and they work fine. Even some cheap ones from amazon or ebay work just fine for 3 or 4 bucks.


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## TGross (Nov 16, 2018)

I'mNew2Frogs! said:


> Would be very interested in what you come up with.


I haven't bought it yet, but I'm looking at this. It's on the cheap end, but it seems like it'll work well with a portable AC unit and a space heater.


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## Socratic Monologue (Apr 7, 2018)

TGross said:


> I haven't bought it yet, but I'm looking at this. It's on the cheap end, but it seems like it'll work well with a portable AC unit and a space heater.


I'd be curious to know how it works for you. All the negative reviews are simply 'didn't work' which is fat better than 'stuck on'. 

I'd use a Herpstat, personally, since I've not ever heard of a failure, and have a handful of them that have been 100% reliable:

https://www.spyderrobotics.com/index.php?main_page=product_info&cPath=1&products_id=80


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## rhino43grr (Oct 2, 2011)

I moved mine to the top of the tank near one of the vents and it seems to be reading a little more accurately. I get readings that are less than 99% now at least.


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## thrain (Apr 11, 2018)

i have one and the humidity just seems off all the time (stuck at high... probably due to condensation on the probe) I've removed it from my tank and just occasionally throw the probe back in to get a temp reading.


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