Niz

Wattle Grove 6107, west and down the hill from Lesmurdie.

The bottom has been done correctly then, the sides should have been beaded as well. It all points to the side seal leaking to me (IMO fixable)

I know it was done correctly as I built the thing 

If it is fixable I will do it. My wife is already making redecorating plans

The tank does have extra beading across the bottom, so 24mm of total join. The water appears under the polystyrene on the right end of the tank and also down the wall at the right back of the tank. There is no water detectable on any edge except the back bottom edge as I cant get to it as of yet.

Once i get the tank away from the wall all will be revealed. Its been under a bit of stress as there was a wavemaker on the tank for some time when it was salty. When that thing was working there was a 5cm wave rolling down the tank! Was mint watching the fish swim with/against the current.

Heres a pic from 2007, check the diff in water levels at each end. I was sure there was a video of this somewhere but can't find it.

Its not the plumbing or the overflow, just refilled slowly and water started dripping again before the water level had reached either the overflow box or inlet pipes.

Anyone here keep reptiles and wants a really big tank? 

Very little damage, only dropped about a bucket of water on the floor.

With the tank half full the leak has stopped. It might be loose plumbing. Perplexing.