(Calciform Shoal isn't a spell.)
At the beginning of your upkeep, Calciform Shoal deals 2 damage to target creature you control.
, : Tap target artifact with converted mana cost X or less.
, : Add to your mana pool.
, 
: Tap target artifact with converted mana cost X or less.
, : Add 
to your mana pool., : Add to your mana pool.
