Should be unlocked after blue science. Most of the recipes involving fish and nutrients are relevant at that point in the game.

You need vitamelange to do anything so unlocking earlier doesn't do anything

If you're playing with Krastorio 2 there's a recipe for Biomatter that requires fish. You need biomatter for military science. In order to make fish you need nutrients and biochambers.

Krastorio 2 does not have a recipe for biomatter that requires fish? Even if it did, I dont modify any krastorio or vanilla recipes and you can make fish well before the biochamber with microgravity fish growth in the growth facility

Never mind, must be one of the ATOM mods that is adding the recipes with fish. Just loaded vanilla SE/K2 and they're gone. My bad.

Ill take a look with ATOM and see if it actually breaks anything, the only compatible i do for that pack is making sure it doesn't break anything, but there should be another way to get fish unless one of the mods from ATOM is using the same name as SA fish breeding

it looks like ATOM adds the biomatter recipe but they do not add a recipe for fish, so I am guessing you are not supposed to automate that recipe, as you get the biomatter recipe that can be automated without fish in chemical science

That makes sense. Thanks for the help.