The thing to keep in mind with Uros is this.
They don't require water dishes except for females that have recently laid eggs.(most species)
Getting most of the water they require from their food. Make sure to keep it moist by misting if not eaten right away.
I did say most of the water they require. The other requirement for moisture should be provided in a sleeping burrow or hide.
A dehydrated Uro will still continue to live. Not nearly as long as his life expectancy however. Many captive Uros can be seen with what is called snalt secretions on their snouts. This is normal, however the usual frequency is not normal. They excrete EXCESS amounts of this mineral. So if they are doing it daily there must be an overabundance of it in their bodies. One cause of it would be dehydration. There is not enough water in their bodies to use it and dilute it efficiently.
I don't know how many times I've heard "but they're from the desert". Sure they came from a more arid climate. Not sand dunes by any means though. They hide in burrows, held together by moisture quite far down. As long as they have the ability to dry out completely under a basking lamp you don't have to worry about dry gangrene or tail rot.

__________________
Mike
"Never worry about numbers. Help one person at a time, and always start with the person nearest you." - Mother Teresa

yea I did know you aren't suposed to give water to them.

i'm not sure i'd be able to keep the substrate deep enogh for a burrow, would just a large hide be suffecient?

In most cases Uros are kept on a thinner substrate that doesn't allow for burrowing. You can provide a piece of ABS piping with some moist moss in it. If you get a piece that you can close at both ends and leave a hole at the top. It should work out fine. A tupperware container would work as well as long as it's dark plastic.

__________________
Mike
"Never worry about numbers. Help one person at a time, and always start with the person nearest you." - Mother Teresa

Try the excavator substrate that Mike suggested. I've not used it myself, but I'm seriously thinking about it. It looks like a pretty good solution to both problems.

Though, I would say based only on the behavior of my own, that if you have hides for your uro, they don't necessarily need to dig. Mine never seemed to want to, even when I first got him and he was still on the sand the old owners had him on. He had the same hide he has now, and hasn't had a bit of trouble converting from sand to paper towels.

In fact, he's a lot fatter and more willing to come out an socialize than he used to be, but I doubt I can attribute that to a simple substrate change.

Edit: Haha, Mike. I took a long time writing that, so now this response looks funny.

__________________
"Let's eat, Grandpa!"
"Let's eat Grandpa!"

Punctuation. It saves lives.

do you bury the burrow (hehe that sounds funny) that he stays in? becuase I don't think I could fill the tank with that much substrate.

this is kinda changing the subject but I have another q, I know I need to get a good UVB lamp but for basking, should I get a basking lamp or heating pad?

i was just thinking it would be easier to keep a heating pad on all night than it would be a lamp..... but i'm not sure, so just tell me watcha' think!

Now you don't need to bury the burrow as long as it doesn't permit light to pass through it (dark in colour).
Definitely go with a basking lamp. Heat pads are no good for Uromastyx.

__________________
Mike
"Never worry about numbers. Help one person at a time, and always start with the person nearest you." - Mother Teresa

And you do not want to keep the light on at night.
For heat without light get a ceramic heat emitter.

__________________
Merlin,
What's Life Without A Little Magic!

where would you find a ceramic heat emitter?

Petshops have them, as well as online where you can get them cheaper.
I get mine at
HerpSupplies.com - Reptile Supplies, Vivarium, Reptile Accessories, Reptile Habitat, Reptile Lighting, Zoo Med, Reptile Supply, Lizard Supplies, Reptarium, Rep-Cal, Flukers, Reptile Bedding, Fresh-Air Habitat, Reptile Heat Pads

__________________
Merlin,
What's Life Without A Little Magic!