I would like to ask if there are more types of clear silicones.
I have seen a Optiwhite tank glued by clear silicone but it was ugly with greenish joins and I saw no difference between float and optiwhite. They said me it was made with bad silicone which tends to yellow if thicker layer of glue is used. But I don't believe it is caused by silicone. I think they used the bad glass. I saw another optiwhite and it looked great. The joins were bluish and not greenish.
for optiwhite tank owners: Does clear silicone in joins tend to yellow after some time? (1-2 years)