The glass on my Neo 90 tank is 1/2" thick. My Large size magfloat has trouble staying stuck and with any good force. Its fine for the light haze that builds up through the week, but around the silicone there is always a harder layer of green stuff that the magnet wont touch. As soon as it hits the silicone, it loses its grip and floats up. What does everyone use for this, I can't be the only one. I guess this is why people get black silicone?
