Rare Reactor Farm Tips

Hey guys, I know in hard mode it’s very easy and straight forward to farm out the ultimate reactors with the way the map shows things, however I’ve been trying to farm specific purple reactors and have found it very difficult to obtain them since I get oversaturated with ultimate ones.

Does anyone have any tips or locations to farm the rare “purple” reactor types? Looking specifically for purple gley reactors but want to utilize this for my other descendants so that I’m not forced into using ultimate weapons in my builds.

Thanks!!