Silicone turning yellow

[Vorog]

I built a 40b sump and used GE1 silicone to glue in the glass baffles. This is not my first sump I have built with that silicon but this is the first time I have ever seen the silicone have a highlighter yellow film on it. Some of it I can wipe off with a toothbrush I use for cleaning my pumps. But some of it it really on there. I know the silicone is reef safe and doesn't have any anti mold chemicals in it. Like I said my other tanks use that same silicone and they have been up and running for 3 years. I let this sump cure for two weeks while I built the stand for my tank. So either it's algae growing on it or something. Anyone else have this issue?

 

[tony727]

Try wiping your glass to see if the same film comes off, might be more noticeable on silicone because its not completely clear. I'm thinking its just diatoms or something.

 

[Vorog]

I wiped the glass and didn't notice anything come off. But on my heater I had a little film on it I didn't have yellow coloring to it.

 

[kyle.nagel13]

I'm interested in what you find out, because my sump is doing the exact same thing. I used the same silicone. I'm not seeing any signs of stress in my saphire damsels at this point, but following along.