an emergengy of sorts, we need to transfer whats in one tank to the other this evening if possible but what can we tarnsfer them in? do we need to float them? if so in what? would a carrier bag suffice?
I'll first make sure the temperature in each is the same. Then half fill a bucket with water from 1 tank and fill it up with water from the other. Then just net the fish put them in the bucket. Then you can put them in the new tank. Is the new tank cycled?
I would also transfer a fair portion of the water from the old tank to the new one. Then it's not much of a change to them.