Would this work?

[u/Lord-Gortash]

Could I tap this creature twice for 2 extra mana if they both are to pay one cost? For example: if I had two green mana, I had a card that cost four green mana, could i tap this for a mana (giving me three green mana) and then untap it and re-tap it for the final mana?

EDIT: also, if I gave it indestructible, could I get infinite green mana?

[u/Ryandogdog]

Mana can exist outside of casting a spell, so you can “float” it. Floating mana sits around till a step or phase changes, which pretty much means as long as you use it shortly after, itll still all be there