OT: need salamander help

We have collected a mass of salamander eggs from a vernal pool in the hopes they will hatch. My 7yo is a huge salamander fan and he is very excited. The eggs seem to be doing well (they look right and the babies are definitely growing/developing) but we also got two small salamander nymphs at the same time that don’t look healthy/strong to me.

We’re feeding them frozen/thawed blood worms and a store bought food made for small amphibians, frogs and newts. The nymphs don’t seem to eat either, though.

The pool is too far away to exchange the water daily though we could do it every other day with a lot of effort. I’ve read you online we should use de-chlorinated tap water and exchange out 50-100% daily. We’ve tried 50% this way.

If anyone has experience in raising salamanders like this, I’d love some advice.

Thanks!

shannon