Seed Shrimp

Nope, only sure way is to nuke it, they hide in the substrate. I gave up and let mine be. Every once in a while I put a slice of eggplant/zuccini on a feeding dish and put it in, then fish it out in the morning full of scuds.

I only see seed shrimp right after a water change, the number die off within 1 or 2 days. They don't really do anything to harm shrimps, trying to eradicate them is probably close to impossible without harming your shrimp. Just let them coexist would probably be the best advice. The populations tends to crash as the water gets dirty. If you have them all the time your water is really clean. There a pen by Gush that helps trap them, not sure how well it works.

OH wait sorry, I got ostracods confused with scuds. Ostracods are fine, filter feeders, if anything it's beneficial to your tank.

I siphon mine off the walls any time I clean. And they looooovvve leaves so I can catch probably 50 or more just taking a half eaten mulberry or IAL leaf out. I got a population boom by feeding powdered baby food. They are harmless they just annoy me.

Add some nano fish, boraras or CPDs.