hi could someone tell me roughly how big cory eggs are and will they be stuck to something or will they floating aound the tank?

They can be easily recognised as eggs and will be stuck to something. They often lay in small clumps on the glass near the bottom to middle.

Mine lay small white or clear(ish) eggs about the size of a match head. I find them on the glass in clumps of 15-20, on a braod leafed plant, on the filter, heater, basically anywhere they want. They ones that are white arent fertile and i leave them to get eaten.

Here is a picture to save a thousand words

some of my cory's spawning

Nice

Unfertilised Sterbai eggs