I just used Aqueion silicon i bought at the pet store for 14.98$, it worked great. I sealed a 75 gallon, i gave the tank 75 hours to cure, and now its full of water and doing just fine
Yup, thats the one. I tried the kitchen and bath silicone I before too. Both the same. Used on more than 6 tanks in the years and no ill effects on the fishes and shrimps.