Dennis,I have to say that I am not exactly in love with your design(and I say that with nothing but kindness in my heart).The bio balls are not really a good idea as they are difficult to to clean and have been accused of massive nitrate build ups.The best way to use a sump is with biological filtration,using algeas like cheato or calurpa.The space you have allowed for filtration is to small to be succesful.Also I have never seen a sump designed with a specific "viewing area".On the up side,if I was going to build a sump I would use the exact tank you have,its perfect.Have a look at this drawing and see what you think.
