+1Is your glass windows silicones directly to your concrete or do you have a steel plate or something
MonsterAquariaNetwork app
I have start building 16/7 and put the fish in the tank at 1/8 at half water level and feel it up at to the top 23/8
I have only very small problem at left window, bottom left corner with a small leak that was repair instantly.
For sealing i have use a Cement-based brushable sealing slurry.
Silicone for the glass to tiles.