James,
Yes, my fish LOVE the new wall, they go in and out of the holes all the time now. I have 5 tiger barbs (3 of which are albino). (All fish are in the photo if you really look including my pleco).
Marian,
The size of the wall is 6 1/2" L X 2" DEEP X 12" HIGH.
Here is the site to where I ordered it:
www.thatpetplace.com
It was shipped fed ex and took less a week!
I'm not sure on the exact size of my tank, I remember when I bought it - I looked all over for a description but the store was going out of business at the time and I just fell in love with it that I didn't care.. and yes mine is freshwater.