Acrylic scratches are very simplistic once you understand the technique. As a matter of fact, you do not even have to remove fish, corals, or rock structures unless access is a problem. I have professionally used and recommend EverClear Transparency Refurbishing company: ETR Home | Everclear Transparency Refurbishing
. You can purchase kits, which I believe contain instructions, but are available online as well. Basically, it's all in the grit steps.