Absolutely fine Andy. Ask as many questions as you need to.
Yes our Acox is similar to the Coxoid. I know the dosage rates are the same.
The way to use Acox is to give it at least 3 weeks before breeding, at a rate of 6ml per 1 litre of water. You give this for 1 week.
If you have young birds showing symptoms of coccidiosis, then do the same as above, but if the symptoms persist, you can give Acox again for a 2nd week, but at half dose. So either 3ml per 1 litre or 6ml per 2 litres.
Even thought Zebra finches are small the dosage rate is still going to be the same. If you deviate from the dilution, then you will make the product weaker (or stronger), and hence it will not help your bird. The bird will drink what it needs, so will therefore get the right dosage rate.
I hope this helps.