mana pool?

[AdamS]

 {Omnath, Locus of Mana} so it says tht mana is not lost through phases does it just tap and untap or is it just there til i use it  once then its gone

[FlickerYourOwnIdentity]

It means that when you get a green source of mana, and you don't use it.  It stays with you until you use it (or until monarch leaves the battlefield.

Lets say you have him out and tap 3 forests and a {Llanowar Elves} for 4 {G}.  You use two of that mana this turn.

When your next turn comes, there will still be 2 {G} mana in your mana pool.

[AdamS]

ok thx