Any thoughts on the slanting of long OF boxes?

[treesprite]

As the title says, I'm wondering what people think about the slanting of the front walls of long overflow boxes rather than having the standard perfectly vertical front walls. I'm wondering if it would reduce waterfall effect and if there would be any other benefits depending on the degree of the slant.

[AlanM]

I think it could be fine.  Here are the negatives I can think of.

 

Harder to clean down in that lower crack if you care to clean there, though.  Small cracks with lots of flow tend to be aiptasia magnets in my experience.  Also, less volume in the overflow box is less margin for adjusting the drains to keep it from flushing and also less opportunity to make repairs to any bulkheads behind it.  You're stuck with those bulkheads in there because you can never put any new ones in or take the old ones out without cutting off the box.  You also have to get the triangular pieces on the ends of the box very exactly made and assembled because it will need to have the same angle on the two sides or else your weir edge will not be level and you will effectively only be using a fraction of the box.

 

On the positive side, you get something with a really low profile in the tank.  You would also get a quieter overflow provided that the front edge of the weir was smooth rather than toothed.  

 

I had a smooth (non-toothed) weir on my 75 gallon.  It was amazingly quiet, but fish and shrimp did go over it from time to time.  Only the little ones, but it made me sad when it happened.  Normally they were dead before I found them in the sock.

[treesprite]

What I am imagining is something that still has a flat bottom, but has a slight angle that is not as drastic as the slant of a typical "inbox".