If you have bought the 3 version before and sold them back , would you still get the 4 version ? <| sep |> I am on mobile and it works . It ' s high traffic at times <| sep |> I ' m going to say Mercury Marauder . I argue it ' s overlooked because of the Crown Victoria <| sep |> Sorry I don ' t have a ton of useful advice for ya , I just don ' t think those snails ram ' s horns ? could do that kind of damage . My first guess would be that you just happened to end up with a tank that had suspect silicone work even before you ever started the tank it just wasn ' t noticed , and happened to fail now . Although the silicone in the pic you posted looks ok from what I can see . If you do try to repair it yourself , definitely do some research first . Unfortunately , new silicone won ' t adhere to old silicone .