I would just test fill it outside of the house. I wouldn't go and reseal just for the heck of it, unless the silicone looks to be in really bad shape, which it shouldn't since it's not a fairly old tank...
I'm awaiting for my leak repair to seal. SO I'm thinking how to do the herbie overflow setup.
The existing bulkheads have an internal diameter of 25mm, however the pipes that come with it and push through to allow hoses to attach end up giving a maximum 20mm internal diameter:
So if I were to only use one pipe as the outlet and the other as the emergency drain would I be able to flow 900gph through 20mm???
Or should I just use both as the outlets and have some form of air valve at teh top to break the siphon if power outage?
Also how do I attach longer pipe as below to the existing bulkheads:
Just silicone pipe onto it with the standard pipe inside anyway? I'm guessing I would need pipe with 27mm ID to slot over?