Try to eliminate slowly but surely the snail invasion. And try to bring your shrimps to a singe feeding spot. The place that has the least water movement in the tank. Stop your filtration system. Wait until water settles. Drop the food in the subtract with a dropper. Wait a while it settles a bit and restart filtration. if you have a lot of fishes this could be somekind of an operation. Distract them before by feeding them floating food. Check if your buddies finds the golden spot. repeat every other day until you have a bunch of them. Then No more than twice a week even, just once... So they continue to wander all over the tank, and keep an eye on the golden spot.
If you have a tendency to overfeed... They will never be at risk.
