Your cart is empty.

    Aquarium: butt- or bead bonding

    Differences in silicone bonding

    In aquarium construction, two different ways of working are common practice when gluing glass panes with silicone: bead bonding and butt bonding. We’ll show you the differences here.

    Bead bonding

    bead bonding

    This type of silicone processing in aquarium construction has long been favored in the past, especially in the production of larger basins. When bead bonding, the glass panes have no surface contact with each other. There are gaps between the panes, which are filled up with silicone. Compared to butt bonding, bead bonding uses up significantly more silicone, which usually translates into a higher price.

    If this method is used in aquarium construction, the higher material usage also means that you can see a lot more silicone, both inside and outside the aquarium. Due to the design, the seams are quite wide and thick. Unfortunately, especially when using transparent silicone, there is the problem of increased algae formation on the large silicone surface inside the aquarium. The surface finish of silicone is slightly rougher than glass, which favors the settlement of algae coverings. This type of bonding is quite difficult to keep clean and algae-free.

    Butt bonding

    butt bonding

    This type of construction has now established itself as a modern standard. In butt bonding, the contact surface of glass and silicone is significantly larger. The stability of the butt bonding is much higher compared to bead bonding, so many aquarium manufacturers offer this construction form even for large aquariums.

    Butt bonding is certified according to a DIN standard. This is important if, for example, you want to take out a glass insurance, as this type of DIN-compliant bonding is usually recognized by the insurance providers.

    In production, when the panes are pressed against each other, lateral silicone beads are produced. Glass basins look particularly elegant when the beads are sliced off cleanly both on the outside and inside. In this way, almost no silicone can be seen in the aquarium and hardly any bothersome algae can form on it.

    silicon with algal onset

    Thick, internal silicone beads are clearly visible in the aquarium. They are difficult to keep algae-free.


    While in the past black silicone, on which algae coverings remain largely invisible, was used as the standard color, nowadays mostly transparent silicone is used for the butt joint with scraped-off beads. This results in a much nobler look. Modern tanks such as the Cube Garden by ADA or the Dennerle Scaper's Tanks are manufactured this way..

    But there are also striking differences in the glass material used in aquarium construction. We cover the different glass types in our wiki article called "Float glass or white glass?" in detail.