Increase plumbing size at the Manifold?

[J Crew]

I'm putting together my parts list for my plumbing. It was recommended by someone at BRS to increase the plumbing size at the manifold. Is this common practice?

For example, I'm running the Varios 8 pump, which will be 1-1/4". But it was suggested to bump up to 1-1/2" at the manifold.

Any input and advice around this is much appreciated. Thanks.

 

[KrisReef]

From your diagram I see 2 V-8's (2700 GPH each) and a 112 gallon tank. With 2 pumps, presumably (for discussion) running at half speed you still have 2700/112 = ~24 times per hour, 578 times/day the water is going through the filtration. Even if the head pressure loss on these pumps going through 1.25" pipes is half you are still going to be moving more water around than you can possibly need, ime. Expanding the diameter of the pipes isn't going to be necessary for flow needs/ purposes, from what I can tell.

I might even suggest that you have too much pump for the tanks. I once put an old pool pump 3000gph on a 150 gallon tank and after 12 hours of running the tank was almost 90F . That was not a DC pump, but the amount of current was crazy. Let's see what other folks say?

 

[J Crew]

Agree, I have more pump than I need. But yes, the plan is to run it at half power or probably even less.

I was thinking there was no need to increase the pipe diameter, but wanted confirmation from some of your guys. Thank you for your input and suggestions.

 

[trainbob]

I believe the rate of flow will be dictated by your smallest pipe. Don’t think increasing the size of a part of your pipes will increase your flow

 

[QuickrdenU]

I think someone at BRS was smoking something. 1.5” is huge for a 100 gallon tank I feel like. Especially with 2 pumps. And most items that run off a manifold are gonna be 1/2” or 3/4”.

If you want really high turnover through the UV(and quieter pump operation) then reduce the number of fittings and reduce head pressure(make the route back to the tank as direct as possible) as much as possible but I don’t think 1.5” is gonna help you with that at all. I’m running 1” on a 200 gallon with 2 pumps and it gets reduced down to 3/4 at the returns. I’m no professional but…

 

[J Crew]

Okay, you all are confirming what I was already thinking. But I thought... I better ask just in case. Thanks everyone for the input.

 

[QuickrdenU]

1.5” costs more than 1”. Especially when ordering larger fittings. That, I’m sure was their reasoning. BRS are marketing geniuses.