Best practice plumbing questions

[finaddict]

I finally got my 75g tank today and will be drilling and plumbing this week. I have Synergy Reef ghost overflow and I would like to glue a 1.5 inch to 1 inch reducer bushing right into the overflow.  I realize this will restrict how much water can flow through the drain lines but from what I can find, a 1 inch pipe can move 960GPH and my return pump (Sicce 3.5) is only rated at 660 GPH.  I want to start my plumbing by reducing the size of the pipe because all of the fittings, unions,  and valves are way cheaper in the 1 inch size than in 1.5 inch sizes.    Am I missing anything here or am I ok to reduce the pipe size right out of the overflow before the first union?

[jayh]

my recommendation would be to reduce it after the union, so you would need to use 1 1/2 unions.  That way, if you want to move the overflow to a larger tank, you can and support a larger overflow.  Just my .02...

[finaddict]

Yeah that is a good idea. The overflow can go with me in that way.  The real cost difference in fittings is for the gate valves.  Huge difference between a 1 inch gate valve and a 1.5 inch....  Unions are only about 5 bucks more for 1.5 inch.

[Jon Lazar]

I would use 1" for the siphon, but I would keep the other two at 1.5". Reducing their size reduces their capacity if they're ever needed.

 

You only need a gate valve for the siphon. The other two pipes should be unrestricted with no valves. So there's little cost savings by downsizing them.