How to introduce warty newts as tank mates?

Hi there,
I have had a Paramesotriton chinensis for a few months now, he is approximately 6 inches long. He used to move around a lot and was curious but lately he has seemed very slow moving and bored.
So, we went to the same pet store that we got him from and purchased another Paramesotriton chinensis. We guesstimated that the new one was approximately the same size. And he is about an inch shorter but must weigh significantly less, however, about the same weight as our old one when we first got him. The newt we had first appears to be a fully grown adult and this new one in comparison must be a lot younger as he seems to be less developed (smaller hands, shorter tail). We put the new one in the tank with our old one and the old one started snapping at and kind of hunting the new one like he does when we put worms in his tank to feed him. So, we quickly removed the new one. We have set the new one up in a smaller tank right next to the other tank and our old newt is just watching and observing the littler newt.
Is there any way that we can introduce the two without having our larger newt kill the little one? Or should we wait until our little one has been fattened up a bit?
We are still pretty new to this so, any tips or hints would be appreciated.

Oh and as a side note, both of them are male and the tank is 10 gallons.

I wouldn´t consider a 10 gallon apropriate for two P.chinensis (quite frankly, not even for one single fully grown adult). They are territorial and certain individuals, as you have experienced, can be very agressive.
Some combinations of individuals simply don´t work. There will be fighting, and death is possible.

Your best bet if you want to try and keep them together is to have a large tank, as large as possible, very heavily planted, with lots of hides and visual barriers. It´s possible that in such a set-up they will find their own territories and ignore each other. It may also not work...

As i said, some individuals just don´t mix well together. Be careful if you put them together again, watch them closely. Also, i would very strongly recommend that you get a bigger tank for the new newt. Anything smaller than 10 gallons is way too small and inadequate for one of these newts (in fact it´s the recommended minimum volume for even a single newt of a small species such as Cynops orientalis).

Oh, one more thing. You should really quarantine the new newt before you even consider putting it back with the other. They are wild-caught in China, and many are ill when they reach the pet-shops. It´s risky to ignore the quarantine period.

Best of lucks!!
And welcome to the forum

I think a 10-gallon is fine for one, but too small for two.

Ideally, the best way to introduce them into the same tank would be to make a new setup that is unfamiliar to both of them and introduce them into the new tank at the same time. This way neither of them already has a territory. However, with both being male you may still end up with them not getting along.

Thanks for your information.
I cleaned out the old ones tank in case the new one tainted the water for the few minutes that he was in there.
And for the interim I bought the new male a 15 gallon tank to quarantine him and to use a home for him until he fattens up so that I can introduce him again when they are closer to the same size and weight.
If its okay I have a few more questions:
1. How long should I quarantine the new one for?
2. When we try to reintroduce the two would a 30 or 40 gallon tank be a better size?
3. If we introduce them in a larger tank and they seem to get along fine when we go to feed them should we separate them into different tanks so they don't try to steal each other's food?

1.Quarantine should be of at least about month.
2.Definitely better!
3.I would feed in opossite parts of the tank. Hand-feeding with tweezers would be preferable.
Don´t separate them for feedings since that means manipulation, which equals stress.

If you find that there is just no way they are going to accept each other, you can always place a glass divider that completely separates them. If you go for a 40gallon, 20gallons each would be very nice. Just a last resort meassure...

I have one Chinensis in a 50gallon and it used to house a second one but after being attacked and wounded, I quarantined her in a 10gallon with plenty of hides, water changes, feedings, etc. Her wound healed but she must have gotten an internal infection or something because she died not long after.

I would perhap house a young Chinensis in a 10gallon, but I don't think it would be suitable for long. I say that you need at least a 20gallon for one adult.