i have a 180 too but a little different set up , being that my tank is a different shape a 4x4 foot print . with a uro brace with a lip under the brace . so i have a custom cut sliding glass lid made with thicker 5 , 8ths glass that sits on the lip . this glass is pretty heavy just because of the size so i dont have to worry much about jumping for now and hopefully a while lol .
but if and when i do i would not put heavy weights on top for the fear of them falling into the tank and breaking it . that could be disastrous .
personally i would recommend designing some kind of custom lid made of plastic or wood with some type of latching mechanism . perhaps using some of that Velcro tape stuff . your tank has the plastic rim on the top which could be easy to use something like that .
or custom nice wood top if your good at that sort of thing . but ya i would advice against putting heavy things on top