Fishing for specific level mats in the Diadem?

So I get the gist. Cloud fishing for the higher level fish. Turn in, desynth for mats. Lake fishing for the lower level stuff. Is there a place/bait to control what level of mats you get? Currently for my crafting jobs I need the level 60 mats. Can I get just those or is it just going to be super random?

Looks like you want Northern Diadem Lake.

All cloudfishing spots have only level 80 fish that desynth into level 80 and level 80 artisanal mats. The Southern Diadem Lake has only fish that desynth into level 20 and 40 mats. The Grotto has the same two fish for level 20 mats, and two fish for level 70 mats. Northern has the two level 20 desynth fish and two level 60 desynth fish. You'll still get the junk level 20 desynth fish but you can ignore desynthing them and only desynth the Pirarucus and Brown Bolos.

Perfect, thanks.