Black silicone has been for a long time considered highly effective, because it prevents the aquarium’s lighting from filtering out. The common opinion was that because of that, the growth of algae between silicone and glass would be inhibited. But it has been proved that for some types of algae what little light gets reflected by the glass is enough for it to grow without problems. Therefore, at least once per year, check the seals of the aquarium even in the most difficult to reach parts, to identify possible algal infiltration, which if present should be eliminated immediately. Small cavities in the silicon seal can be filled with special epoxy resins, to prevent algae from infiltrating the seal again. In case the infiltration of the algae has already compromised most of the seals, you can remedy by attaching an additional strip of glass on the outside. In this way, you avoid emptying the aquarium.