[karimwassef]

Ok. I brought this up a while ago but since I'm not plagued, I don't need to try it out...

Since dinos settle down under light, why not run a dark system with a brightly lit section (big tub or container) with a lot of surface area for them to settle down on. Let it run for a while until the container is plagued with them. Maybe even put lots of eggcrate so they have lots of space to settle down...

Then! Abruptly disconnect the container from the main tank and "export" the dino crop into the drain. Harvest them and throw them away.

Some will remain, but maybe it's enough to give the other inhabitants a step up?