Top Down Tank Shots

[d2mini]

What are you guys doing to shoot top downs with your slr?
I've seen some people use some sort of acrylic box. Is this the most common way? Any tips on this or other techniques appreciated. Also, if doing the box thing, tips on building something or link to purchase would be great.

The last thing I want to do is drop $5k of equipment into my tank. :eek1:

Thanks!

 

[qfrisco]

Do you have experience with working on acrylic? Check out Marc's Topdown Photo box here: http://www.melevsreef.com/topdown.html