There is a small leak on the seam of my sump no fish in the tank yet or corals its cycling but can i fix this with a little bit of silicone or should i look at getting a new sump
I’ve never repaired a cracked seal but most people agree that you can’t use silicone on top of silicone. You need to scrape the existing silicone and rebuild the tank completely.
Since it looks like it’s a small, standard size aquarium, I would just buy a new one for peace of mind.