2 return pumps? What are the pros and cons???

[SandJ]

I seen a BRS episode where they talked about some people running 2 return pumps. I never really thought about it, but in a way it makes sense. In case one goes out you still have flow.

Anyone here run 2 return pumps?

What are some of the pros and cons?

I have 2 overflow and 2 return bulkheads, would I just plumb a return pump into each return line?

 

[KrisReef]

I have two. If one fails the other one is still running. I have plenty of overflow capacity and only one sump with both returns in it.

If one stops, my return will then siphon water back to the sump so the water level will change if one stops.

 

[mtraylor]

If you hard plumb 2 pumps you can plumb in a way with valves should one fail. You turn a couple valves and the one pump will severice both returns while u get spare.

Me i hard plumb one pump that runs everything like return, reactors, etc. I have a spare in closet.

You should always have a spare return pump. That is my advice no matter how you plumb. If you use 2 pumps operating at one time you will need mor space to accommodate

 

[Silver14SS]

Pro is redundancy, always nice to have another layer of security.

Cons are more complicated plumbing and maybe more heat or noise.

 

[B's Reef]

Most of our tanks have 2 return lines. You can easily plumb one return pump to each return line. Instead of one pump to run both, you can get 2 pumps half the size. If one ever dies while you are asleep, out of town or at work, the tank will at least still be connected to life support in the sump. Costs a little more, but its worth it to have more redundancy. Go the dc route to avoid excess heat and noice.

 

[ksed]

The concern with running two is if one fails then the water will start to backflow. One way to do it is to add check valves but these require maintenance. Not sure if there’s another way ?

 

[cedwards04]

So I run dual return pumps mostly bc I work out of town a lot. It could be up to a week before I could get home to replace a broken pump. Having dual returns ensures I always have water circulating. I used 2 smaller pumps instead of one large one, this makes the cost a non issue. Very little cost difference. I did install check valves on each return line incase of pump failure. This will at least slow down the siphon enough even if it is dirty and can't seal completely. I also run an apex with dual eb832's on separate gfci circuits. I have power heads and heaters on both incase a breaker trips I still have back ups.

 

[WVNed]

I use 2 returns and 2 pumps. Each return has an air admittance valve to break the siphon. They never flow backwards.

 

[Silent]

Cant really imagine a con.

 

[Mrx7899]

I run 2 return pumps one pump for each return line.

 

[cedwards04]

Only con I can see is you gotta clean 2 pumps instead of 1. That's really about it.

 

[120reefkeeper]

I’ve been running 2 return pumps for years and years and years! Lol

 

[mikedb]

I use two return pumps, each behind a true union check valve and a common flow meter. I live in a colder climate and have my heaters in my sump, and would be concerned about a loss of flow for any prolonged period of time.

I only run one pump at a time, since at my head pressures (basement sump) the second pump doesn’t add much flow. It is certainly not worth the extra noise to run both at once.

While a significant added cost, my philosophy is to install redundant systems wherever possible, especially for equipment that I would consider life supporting.

This system already came in handy once, when one of my Varios 8 pumps failed after 6 months in service (power supply failure). My controller sent me an alarm and started the second pump. I was able to order a warranty replacement power supply (3 days to arrive) without any impact on the tank.

 

[jcricket]

One pro is that you can get equal flow out of both returns. I always seemed to get more flow out of one side with only one pump. Sure, I could add a valve, but that was a stop gap to me. I also ran two smaller pumps rather than a single larger pump. I think it was a bit quieter. Cons, I think just a little more energy and possibly a little more heat. I never really noticed these, but strictly speaking I think this is the case.

 

[Bruce60]

Two pumps: Redundancy is the big positive. If one pump goes down you still have some flow. Negatives are need more space in sump, uses more electricity and generates more heat.

One pump: Positives are less space, electricity and heat generation. Negative is if the pump stops flow stops.

I have siphon stoppers on both returns to break the siphon when the return pump is off, but I still get water coming down from the display until the tank level is below the overflow. Rather than check valves, which have a less then stellar reputation, you just need enough room in the sump and siphon breaks on the returns.

I ended up going with one of the Maxspect Duo pumps for the return in my new 150 gal. It is a single motor with two impellers each driving one of the returns. Still a single point of potential failure, so I have a backup on hand. But even if the return goes down, I have separate circulation in the display and between the sump and refugium, so I will have circulation in two separated systems until I can restore the return pump.

 

[ca1ore]

I’ve never personally bothered to run dual return pumps. My approach has been to use decades-reliable external AC pumps. I do keep a drop in replacement on hand, though it’s collected quite a lot of dust in the almost 10 years it’s been sitting forlornly up on that shelf. In fact, in the almost 30 years of reefing I’ve not had my main pump fail.

The current crop of DC pumps don’t really fit my needs, though if I did use one as my return, I would probably reconsider redundancy. Not clear to me that running dual pumps necessarily uses more electricity or generates more heat. Presumably you run two at half the speed you would be running one at?

 

[SeaJay]

The concern with running two is if one fails then the water will start to backflow. One way to do it is to add check valves but these require maintenance. Not sure if there’s another way ?

One small hole drilled fixes that. I run two pumps and can just switch one or both off at any time and it never flows backward. No valves or safety checks needed.

 

[symon_say]

About backflow, just drill a hole in the top of return pipe, add 1/4 hose and set it about 1/4" over water line, if anything fails syphon is break instantly.