“If it ain’t broke don’t fix it” plays in Ixen’Hesjing’s mind as he continues to maintain concentration on the geyser with the express purpose of making some roasted ants and/or ant popsicles.

Spoiler: Actual First Round
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Just gonna keep geysering since I go before the ants.
(16d6+18)[73] or (3d6+18)[23] Fire Damage for the ants left in the geyser.

For the things outside of the geyser but within the freezing downpour around it: DC 31 Reflex or (10d6)[41] Cold Damage, and entangled. I do the whole messing with Resistances with the damage and they take (2d6)[8] cold damage if they have evasion.