Evict the cardinals, or put the pregnant cherries in a maternity tank.
I have found the best ways to catch shrimps in a planted tank is to use a chopstick and a small net. Get the shrimp to crawl onto the chopstick, and then scoop it up with the net. Somehow, I have more success with younger shrimps rather than the older ones with this technique, though...
/John
Bookmarks