I think you will be a lot happier by going with pond armor rather than using drylock. I can't wait to see this started.
At the certain point that he is expanding the tank, the width of the tank will increase, which will increase the pressure exerted on the glass.greengiant;2477215; said:pressure does not increase by adding space to the back. water pressure increases by adding height. the added height is not here he is adding to the depth in the addition but that is below the glass so has no effect on it. he isn't changing the viewing window at all so there will be no added load on it