4ft Tank Stand Bending?

I would check my water level first to see if the tank is level . surely if the water is level then the stand is not bending?

 

Tank / water is level...just measured it...The ground to tubing is 61mm & 64mm in the middle. .So it could be the tubing was bend...

 

I am an electrical engineer, not a mechnical engineer; but I believe your stand was like this for a while.
Imo 25 square tubing with 4 legs only should be fine for a 4ft tank. Not sure why your sketch indicates 1.44m though, 4ft tanks are 1.2m
Whether you have a time bomb ticking, nobody will be able to tell with absolute certainty.

Personally I don't like tanks residing on a frame only, so I normally do the following.
-use adjustable feet (you get inserts for 25, 32 ...etc from Builders warehouse (or others)). These will help level the stand.
-use one sheet of polystyrene on top of the stand
-use 21mm industrial (or marine) plywood as a base on top of the first layer if polystyrene.
I usually paint the plywood with fibreglass resin and 2 layers of Velvaglo for extra protection against water.
-use a second sheet of polystyrene on top of the plywood
-put tank onto the lot.

Ultimately it is your choice, ...leave it as is or
or go through the exercise of changing the setup.

 

Thanx...That is good advice

 

jcl +1, and i like if me stand has cross brace aswell at top of stand. lol i am building a stand this weekend i have extra 75mm square tubing laying around so i am using that to build my stand for my 5ft