5ft tank cracked bottom panel... Newer bigger DIY help needed

How do I fix the tank or how do I (with your help) design something that will defo be a easier shape but double the size... obviously

A friend I knew years ago had a 1mx1m x1.5mhigh cube tank, was a hassle to clean but the liters made it possible to have some seriously large discus as a group

Who can chime in on shapes and design to maybe get a 500L to 600L tank built?

What do I need to consider? What is the strongest shape? Max height that would still work easily? Preinstalled filter box yay or nay?
Width and depth?
A tank for massive parrots or cichlids or a giant planted community ? I like to change it up every few years

 

Something like this? 80cm is a bit high, possibly even for braced panels
Glass is going to be damn heavy

 

Gravel substrate is usually about 5 to 7cm deep...and the top 4cm isn't filled so I hear you on the 70 ->>effective water depth of 60cm

Advice and coaching on how to build, how to finish off etc? I've filled the tank so we'll see

 

I would just add a 6mm floating base as it but have a look at your seems the do look a bit old.

Also make sure the tank is perfectly level before adding any weight to it.

 

Thank you-- getting the base sheet is difficult -- I've been thinking if I take it to 50cm high, 65cm wide by 150cm that adds a lot of volume