So I'm raising some Pacific Tree Frog tadpoles from eggs. About 30.

I did this last summer, with about 100.
98 of them survived.

I'm having a harder time this year. The eggs I hatched seem to be a bad lot, with many runts and sickly tadpoles.

Any suggestions as to how to keep them healthy?

And how can I construct a terrarium to keep a few of the adults, once they have formed?