The main problem to solve here is, as you might have guessed, the radiant drought.
Items:
0*: Cracked Crystal Tank
1*: Dim Crystal Tank
2*: Warm Crystal Tank
3*: Glowing Crystal Tank
4*: Shining Crystal Tank
5*: Radiant Crystal Tank
New part of forge/alchemy machine: Compressor
How it works: Equip a Crystal Tank in either a Trinket Slot or a new "crystal tank slot". As you go on your journeys throughout the Clockworks, your equipped Crystal Tank gains heat the same way other items do. When a Tank is filled, it can be Compressed to produce 10 of the fire crystal of that star level and leave you with an empty tank.
How to get one: Crystal Tanks would be available as mission rewards at the same points as fire crystal recipes.
i write something similar about Heat not fire crystal. If we can compare the ideas the game would be better