Ricardo, how thick is the glass? You only need new magnets if the glass is thicker than 2/3rd inch. The factory included magnets work for 1/2" just fine and if you have 3/4" you have to replace the magnets the pumps come with with 2 sets of 6025.500. A lot of people ask why we don't just include the stronger magnets, the reason is mostly that if the magnet is too strong it pulls on the impeller causing vibration, with the magnetic levitation magnetic fields affect the balance, so they include what will work for most people on the more common glass sizes.