Newbie question from an experienced hobbyist on return pumps

[Fred Phipps]

I’ve been in the hobby about 8 years and have done a few set ups with HOB filtration like large aqua clear filters. My first tank with a sump was a 125 gallon and the previous owner sold me all his equipment that he was using. So I’ve never given much thought to return pumps.

My current 40 breeder has a pump I got at petco about 10 years ago when I worked there and got it on clearance. It’s a “quiet one” pump. The sticker on it has completely faded so I don’t know GPH or anything else about it. It seems to work fine but I am curious as to the importance of a good return pump. And how many GPH should turned over and how to calculate loss of GPH with plumbing.

Any insight is appreciated! I’m scanning the web now for info as well, just looking for personal opinions!

 

[glb]

I have the same pump (2.0 I think) and I believe it runs at 250gph. The standard advice is 10x the number of gallons on your tank. Remember though that you’ll have powerheads in the tank too and those count. If you google calculating head loss you’ll find some formulas that take into account fittings, turns, size of plumbing, height, etc. I can’t remember the exact one I used but they’re very helpful.

 

[Blue Spot Octopus]

For a 120 tank I would look at Eheim 1260 or 1262, Fluval SP4, Iwaki 30. All three of these are very reliable, I am not familiar with DC pumps. So I am sure there will be some good recommendations for them as well.

 

[theMeat]

The old way of thinking was/is 10x display tank volume gph
The newer way is 3-6 x

The advantages to 3-6x are clear to me, plus you get less heat and noise.
The logic is...
Macros have more time with water to uptake nutrients, and getting gph closer to the gph your skimmer can process

Don’t forget to add head pressure into your equation, and can tell you that aside from eheim, probably all manufacturers exaggerate their product’s gph output

There’s a lot to learn and the hobby has made huge advances over the last decade

 

[Fudsey]

From what I remember, head pressure is how many vertical feet plus 1 foot for every 90 elbow used. If I remember correctly

 

[theMeat]

Probably less for each elbow, because unlike drain/gravity fed, the water is under pressure and organized, but yeah, about right

 

[skim]

There are 2 terms that seem to always get mixed up, flow rate and turn over rate. Flow rate is within the Display and is what one tries to reproduce that happens on the Reefs. Turn over is the flow of water from sump into display. Turn over should be judge by what is in your sump and the turn over within your Skimmer, too fast is no good and to slow can be a problem also but hard to do. Turn over for your display tank should be no less then 1 volume per hour, so 100 gal no less then 100 gal/hr I would not go more then 5 times as too fast and Skimmer suffers and if you run a DSB in sump or have Algae for nutrient remove, too fast and they will not be able to do what you want very well.
Flow rate in the display I would say 5 time to 50 times depending on your inhabitants.
Flow rate is far more important then Turn over rate.

 

[theMeat]

There are 2 terms that seem to always get mixed up, flow rate and turn over rate. Flow rate is within the Display and is what one tries to reproduce that happens on the Reefs. Turn over is the flow of water from sump into display. Turn over should be judge by what is in your sump and the turn over within your Skimmer, too fast is no good and to slow can be a problem also but hard to do. Turn over for your display tank should be no less then 1 volume per hour, so 100 gal no less then 100 gal/hr I would not go more then 5 times as too fast and Skimmer suffers and if you run a DSB in sump or have Algae for nutrient remove, too fast and they will not be able to do what you want very well.
Flow rate in the display I would say 5 time to 50 times depending on your inhabitants.
Flow rate is far more important then Turn over rate.

One times an hour turnover will result in problems. Or at least it has for me a few times. Get it up to 3 x or more, and problems went away. And flow rate is more important for most coral, but not for most fish.

 

[ca1ore]

I think most of the reasons folks come up with to 'justify' various flow rates from sump to tank are phooey-logic. I have never seen any credible explanation for matching main pump flow to the skimmer; and arguments that the flow is too fast for algae to extract nutrients just makes me giggle. Assuming one puts things like heaters and chillers in the sump, then flow must be adequate to ensure proper temperature between the two bodies of water. It should also be high enough to affect acceptable surface skimming (type of skim box affects this also). Beyond that .......? 3X is more than sufficient.

 

[ca1ore]

BTW, to the original post ..... there have been many versions of the quiet one pump. Really early incarnations used a base Grundfos direct driven pump that was red in color, a heat monster and prone to failing. They subsequently charged color to blue, but with the same pump. Then the line got completely redesigned, switched over to a different motor and magnetic drive. If you have one of the old Grundfos models, toss it! Otherwise good to go.

 

[theMeat]

I think most of the reasons folks come up with to 'justify' various flow rates from sump to tank are phooey-logic. I have never seen any credible explanation for matching main pump flow to the skimmer; and arguments that the flow is too fast for algae to extract nutrients just makes me giggle. Assuming one puts things like heaters and chillers in the sump, then flow must be adequate to ensure proper temperature between the two bodies of water. It should also be high enough to affect acceptable surface skimming (type of skim box affects this also). Beyond that .......? 3X is more than sufficient.

Have done plenty of experimenting on many dif tanks. Where the only thing that was changed was turnover.
On a system that relies on a filter sock upwards of 6 is better.
On a system that runs no sock lower than 6 is better
Cheato likes more flow, and caulerpra likes less. Cheato also likes a red/blue grow combination, and caulerpra likes daylight, but that’s s whole separate subject.
The bigger the system, the lower you can/should go, with 3x being as low as i’d Recommend
Matching the size of the skimmer to the return gph is not as important on systems that largely rely on fuge or algae scrubber for nutrient export. A good idea on systems that have medium fuge and/or scrubber export. But pretty critical on systems that rely on carbon dosing

 

[ca1ore]

Have done plenty of experimenting on many dif tanks. Where the only thing that was changed was turnover.

As have I, it's hardly rigorous though . Don't want to divert this chap's thread. Happy to debate this with you elsewhere. I don't think matching skimmer to return is important in any system; seems like folks that advocate this fundamentally misunderstand how the skimmer works (I've posted this extensively over the years on that other forum).

 

[WWIII]

A return pump isn't all that important until it stops working. Then working backwards from that it's very important. Eheim and sicce are 2 great brands for this size tank/sump for internal pumps. Iwaki is great for externally plumbed return pump.

I have all 3 on different tanks and for different uses. Really they are all very good pumps. I most recently went with a Sicce Syncra 3 for my 40 breeder quarantine setup. It is very quiet and has good turnover imo. Somewhere between the Syncra 3 or 4 would work well, or similarly sized eheim.

 

[jasonrusso]

On my 210 I run 2 Eheim 1262. They are rated for 960gph. I'd bet after the head loss they are in the 450gph range. I recommend using flexible nylon tubing. It's cheap, easy to clean (you can't get a brush around Pvc elbows) and has less loss because the bends are smooth and not 90 degrees. I've done it both ways and the tubing works better.

I run 2 pumps for redundancy. They aren't going to fail at the same time and the tank can get by on one pump for a while so you can come up with a solution.