Kitchen and Bath silicone has an antimildew agent and definitely should be avoided.
"Silicone II" I thought
might have some agent, but I don't recall the labelling anymore. Which would explain the "not for use on aquariums" disclaimer. That's why I avoided it. I read the label several times, there is no such disclaimer on the tube on "Silicone I". Darn it, now I don't remember, I'll have to read it again.
But nonetheless would the presence or absence explain a discolouration?
I'm kind of thinking that could be a different issue.
Hey where is a good place to find the GE1200 anyhow? I have trouble finding that stuff. If I could have found that at HD or Rona or where-ever I was that day when I was looking I would have used that instead, but there was none that I saw.