Return pump questions

[DiscusnAfricans]

I have an Aqueon Pro Flex 4 sump with a Mag Drive 18 return pump. The tank has two 3/4" returns. Two main questions:

1. Would there be any advantage to using 2 smaller pumps since I have 2 returns? Using the current pump is the easiest and preferred route, but curious if using 2 smaller presents an advantage.
2. If I use the single pump and split the return line, is it better to split closer to the pump, or further from the pump?

Thanks.

 

[duanes]

I like using one pump, but keeping others as spares in case of a problem.
As far as splitting flow, I doubt that it matters where, I have split flows both ways, near the pump when sending flow to separate tanks, or at the outlet to the tank to spread to flow.
Currently I built a DIY manifold to spread for across the entire width of my 180, for riverine cichlids.

As you can see, I don't use drill holes for return flow, I like a lot of surface agitation, and oxygenation so set flow ports above the surface for my situation.

 

[DiscusnAfricans]

Appreciate the input and example.

 

[TheWolfman]

Using two return pumps is a good idea if you want redundancy in your system incase one fails, your tank will not crash. You can also get more flow out of two pumps then one for a few reasons. There will be less restriction due to plumbing with independent return. The larger the diameter the pipe the less work and head pressure on the pump. So even with two smaller return pumps you would still have more flow inside your aquarium.

 

[DiscusnAfricans]

Makes sense, thanks for the details. So 2 Mag Drive 9's would be better than a Mag Drive 18. I'll just have to consider the cost but it's useful information.