Please don't buy clown loaches as snail control. That's an old school recommendation that neglects the needs of these smart, social fish, which get very large, need groups of at least six because they form social bonds and a strict hierarchy, and suffer when kept in ones and twos and are kept for snail control rather than having their needs met. They aren't suitable for most home aquariums, unless you have a tank of at least 100 or more gallons and can house six or more for their lifespan.
Check out how big clown loaches can get when kept well. These fellas are in an 800 gallon tank:
You can manually remove them and reduce the population by ensuring you don't overfeed, and cleaning the substrate often. No excess food means no food for the snails to explode in popuation. There are also snails traps on the market, and a lot of DIY snail trap methods out there to help you reduce the current population.
They're Malaysian Trumpet Snails. Having a few in the tank is actually helpful since they turn the substrate and help clean up by eating excess organics - I added some to my sand tanks deliberately for that purpose. Admittedly, your population is out of control! LOL. But you can manually reduce it without turning to clown loaches. A few assassin snails could also help.
