We have a 4ft cold water tank, we have 2 large goldfish (12cm+) and 8 small (5cm+) goldfish.
We have had them all since roughly fathers day but the last couple of days i have noticed the larger 2 have been displaying some different behavior.

1. The are randomly just swimming very close to each other for small periods of time, side by side.
2. They chase & nudge each other
3. They both seem to 'twist' in the water while darting around for a short period then go back to normal.

I have looked briefly at google which suggests they could be ready to mate and that the female would lay eggs into the water and the male would fertilise them.
I can't see anything in the water, does it sound like they 'could' be ready to mate?

If they do then what do we do with the eggs? Do i let nature take it's course and if they get eaten they get eaten? Do i spend $$ and buy one of those net things to float in the tank?