Hello and Welcome aboard.
Plenty of information here or just ask questions.
You do realise you shouldn't be pairing two blues together as the blue gene in Australia is still weak. So a blue and split is the best pairing. Young blue gouldians require a good vitamin and mineral and amino acids just to get them through their first moult but continuing after is recommended for all your gouldians. I use the power form and lightly dust on soaked or sprouted seed. Others use the liquid form and add to their drinking water. Both are good but a little bit goes a long way.