"Fish safe" Silicon?

[Hillsy]

Just wondering if anyone could recommend any silicon to use to seal pipe work and a viewing window I am cutting into my IBC fish tank? Is there a special "fish safe" silicon I need to use or will ordinary roof and gutter silicon do the job? Also do I just use standard PVC glue on pipe joints?

[Murray]

I prefer to use Sikaflex but there is an aquarium grade silicone.
Sikaflex is a really good product.
It is better to use the high pressure "green" pvc glue. It is thicker than the ordinary stuff and sticks really well.
If you wanted to be very particular use a primer with it.

[orcy2010]

any window and glass silicone is fine, as are any others, asn long as they dont have mould inhibitors in them.

only problem with most "aquarium" silicone, is they are only guaranteed to bond glass to glass, so may not be appropriate for your job. Just remember to let them set really well.

Any PVC glue will be fine. theres a couple out there guaranteed for potable supplies (a green one or a clear one i think). but as long as you let it set for at least 24 hours, it should be fine.

[Neil Bell]

Go to Bunnings and buy Bostik silicone sealant for glazing and sealing windows.White and yellow tube. It is way cheaper than the other product recommended for aquariums and does the same job. A professional aquarium builder I know has always used it for years without a problem.