Will the new light be the same length as the one you have in the first picture? I don't think that looks to bad. With that new light you are getting you should be able to grow a red plant to replace the fake. Buy a good light, a found out the hard way, is the most important thing to do. It is also cheaper than diy lights.I have settled on a 24" coralife 65W light and will just have to deal with the fact that I'll have 2 inches of bulb hanging over the side of my tank.
I cannot for the life of me find a glass canopy for my 20 gallon hex.
My driftwood won't stop leaking tannins
oh, p.s., that is a fake red plant in the background. It and the ornaments my boyfriend insisted be in the tank will be MIA upon the next update. Muahahaha...
For the top you could go to hardware store like Ace and have a couple of pieces of glass cut, 2 or 3. The back with the light 1 piece. Then a section to be lifted up and perhaps another section. Then you can get the suction hangers to lift the glass.
For the problem with tannins I have found a bag of Purigen helpful. It is to be put inside filter. If you don't have that option perhaps putting it near the output or input of the filter would help.