Our Turbo (Turbo spp.) snails come from tropical waters and thrive in aquariums. They can grow to up 6" and have a voracious appetite. Luckily they crave algae, and lots of it. Depending on the amount of algae in your system we suggest 1 - 2 per 25 gallons. Larger aquariums - 125 gallons and up can have more than 2 per 25 gallons because of the additional live rock to graze on.