I had faced similar situation before. The entire tank is full of apple snail. may have over 100 tiny snail at max.
Increase CO2. Snail reproduce slower in acidic water. And manual removal can control the numbers. you can crush the snail shell and they become delicious food of the shrimp. Sometimes I saw my blue shrimps KO those apple snails by themselves.
Don't recommend you to add 娃娃, these fish will eat shrimp...
Other medicine also no good for shrimp.
It will be a long tough battle Wish you luck.
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