After the first small chemical treatment (can never be completely avoided) I have the filter started up and was thrilled: This glass filters out particles instantly. For larger pools, it takes little to the water through, but the water was clear the same day and the pool was ready for use. In sand, it took longer and the water was not as clear danch. If it takes another 10 years (as the manufacturer claims) works so clean, that was a good investment.
Shipping and contact both went swiftly. I'm really satisfied.