I use my bs screen and turkey baster. I scoop out some larva of the water they live in. And its preety nasty, stagnant, dark water. That's what they like.then I hold my screen over the water and pull some up with Tb and drop through screen . I'm trying to remove waste, bugs, etc. But not my larva. I keep it up till I'm satisfied. Then I pour the larva in the screen and rinse. After wards I pour in container with distilled water and just add when ready. just suck some up and water and all or pour in screen and add.