When my ballast went down in my JBJ 24g I looked for replacements. Seems as if they were too old and I had to buy a new hood. $$$ but I did some searching and found ProLEDSupply (.com) and found a direct fit for my tank. I would suggest them, very helpful, and when one strip didn't work I emailed him and got another.
I have pictures of it but don't know how to post them on here.
Also, I did a quick search and looks like RapidLED.com has a direct fit as well.