05 WRX PPP - Collant top up
 

Just checking coolant/oil the other day and noticed that the plastic coolant expansion tank was just below the min mark. The other tank/radiator is totally full.

Once warmed up the level in the expansion tank rose to between min and max. Is this normal or should I top it up so it is above min when cold.

The next question is which coolant to use - done a search on here but to no avail. The stuff in it is green so I am guessing a 50/50 mix of green anti freeze will do the trick. Subaru garage is 40miles away so have bought some green comma extreme stuff. Will this do the trick? Have had loads of conflicting advice re mixing colours. Was told that blue/green is ok to mix but red has to go with red?

just use water as the mix of antifreeze and water will be strong enough to cope with been topped up as for the levels i wouldnt worry about it to much

Thanks. Does anybody know the correct coolant to use?