Another approach involves turning the top into the front (flipping the tank 90 degrees) and attaching a frame for sliding glass doors ie make up a timber sliding door frame (for sliding glass or Perspex doors) , turn the tank on it's side (top becomes the front) ,
remove the mesh lid (bin it) ,
fit the light fittings to the PLYWOOD false ceiling (top under glass ceiling)
ie see this generalized layout :
materials :
* sheet of 3/4" marine plywood offcut , precut by the trade desk at your local hardware shop (for front and new tank CEILING (under glass ceiling)
* soda glass 6.5mm thick cut to size and smoothed on the edges , holes predrilled for finger holes / lock
OR
Perspex 6.5mm thick or acrylic 6.5mm sheet clear (UV STABILISED) with smoothed edges and predrilled holes
* plastic tracks ie https://www.cowdroy.com.au/product/p02624-plastic-track-set