1 or 2 Return pumps for the one sump 2 tanks setup?

[Levinson]

Hi, I'm currently in the process of building a new one sump + 2 shallow tanks setup (Link to my build thread).
One of the things I need to decide is choosing the return pumps.
I will be needing 2 hoses feeding the tanks, one each.
The water volume of each tank works out to be about 120 liters (31.6 gallons).
I'm looking at at least 4~5 times turn over per hour. So about 480~600 l/h (127~158 ghp).
The tank is about 90cm (3 feet) above the sump bottom and I'm guessing the horizontal distance would be around 45cm (1.4 feet). Soft tubings will be used for the plumbing.
I'm based in Korea so the availability of products and the prices may differ from elsewhere.

Some of the contenders I have in mind are...

1. One strong enough DC pump, split it with Y connector to feed each tank. I'm looking at 4 DC pump options at the moment.
1) Be on the lookout for good secondhand deals.
2) Locally made DC pump with 2 years warranty.
3) Red dragon copy with a year warranty.
4) Jebao with 3 days warranty (but cheap).
My concerns for the one DC pump option are,
(a) how difficult is it to have an even split of flow? & how would one go on about it? put ball valves? (don't want the gate valves, they cost too much). Won't it be difficult to gauge the flow?
(b) does the Y split hinder and reduce the flow rate? If so, by how much?

2. Sicce Syncra 1.5 * 2 : 23w, 1350 l/h (357gph)
Heard only good things about it and they are reliable. According to the graph, this will provide enough turnover but they say that the manufacturer's claims need to be taken with a grain of salt so I wasn't sure if this would be powerful enough. I checked with the importer and apparently, they don't import the 2.0 version (it's the only model in the Syncra Silent lineup that is not being imported to Korea! They import the rest of the models). The 2.5 version is far too big for me.

Honorable mentions:
- One Sicce Syncra 3.5 + Y split: too much flow & power usage (& one 3.0 is pretty much the same as having two 1.5s, at least according to the spec sheet)
- One Maxspect Turbin Duo 6k: would have been good if it was a bit cheaper. I'm too cheap.
- One Sicce SDC 3.0: not imported here & too expensive.
- Other fancy name DC pumps like Vectra: ....too expensive.
- Use some cheap Chinese AC pumps + add the 3rd pump with an Y split that feeds to the 2 tanks to make sure I have enough flow (and backup): too many cords and power usage.

Any feedback's much appreciated. Thanks.

 

[Dburr1014]

It would be so much simpler to run 2 small pumps. So much easier to dial in each tank.
Jaboa are cheap, but I do run a sicce myself. Never had a problem with it and it's been 4 years.

 

[reefermadness441]

Hi, I'm currently in the process of building a new one sump + 2 shallow tanks setup (Link to my build thread).
One of the things I need to decide is choosing the return pumps.
I will be needing 2 hoses feeding the tanks, one each.
The water volume of each tank works out to be about 120 liters (31.6 gallons).
I'm looking at at least 4~5 times turn over per hour. So about 480~600 l/h (127~158 ghp).
The tank is about 90cm (3 feet) above the sump bottom and I'm guessing the horizontal distance would be around 45cm (1.4 feet). Soft tubings will be used for the plumbing.
I'm based in Korea so the availability of products and the prices may differ from elsewhere.

Some of the contenders I have in mind are...

1. One strong enough DC pump, split it with Y connector to feed each tank. I'm looking at 4 DC pump options at the moment.
1) Be on the lookout for good secondhand deals.
2) Locally made DC pump with 2 years warranty.
3) Red dragon copy with a year warranty.
4) Jebao with 3 days warranty (but cheap).
My concerns for the one DC pump option are,
(a) how difficult is it to have an even split of flow? & how would one go on about it? put ball valves? (don't want the gate valves, they cost too much). Won't it be difficult to gauge the flow?
(b) does the Y split hinder and reduce the flow rate? If so, by how much?

2. Sicce Syncra 1.5 * 2 : 23w, 1350 l/h (357gph)
Heard only good things about it and they are reliable. According to the graph, this will provide enough turnover but they say that the manufacturer's claims need to be taken with a grain of salt so I wasn't sure if this would be powerful enough. I checked with the importer and apparently, they don't import the 2.0 version (it's the only model in the Syncra Silent lineup that is not being imported to Korea! They import the rest of the models). The 2.5 version is far too big for me.

Honorable mentions:
- One Sicce Syncra 3.5 + Y split: too much flow & power usage (& one 3.0 is pretty much the same as having two 1.5s, at least according to the spec sheet)
- One Maxspect Turbin Duo 6k: would have been good if it was a bit cheaper. I'm too cheap.
- One Sicce SDC 3.0: not imported here & too expensive.
- Other fancy name DC pumps like Vectra: ....too expensive.
- Use some cheap Chinese AC pumps + add the 3rd pump with an Y split that feeds to the 2 tanks to make sure I have enough flow (and backup): too many cords and power usage.

Any feedback's much appreciated. Thanks.

As far as your balancing goes. Just install a gate valve in the shortest linear length pipe. If one pipe run is closer to your first tank, most of the water will go that direction. Just add a gate to throttle flow and divert more to the longer run

 

[dmsc2fs]

2 small pumps. Just one you get 1 pump dialed in between the two tanks you will get a bit of algae in the return pump, or a snail, or the wind will blow the wrong way. You will be back to trying to fiddle with two ball valves trying to dial it in again. Have an espresso and before you are finished with it you need to start again due to a bit of algae, a snail....

I guess all the above is assuming you are trying to have a quite return overflow? If you don't care about the gurgling and sucking noise you could ignore the above and a single pump would work.

 

[Levinson]

2 small pumps. Just one you get 1 pump dialed in between the two tanks you will get a bit of algae in the return pump, or a snail, or the wind will blow the wrong way. You will be back to trying to fiddle with two ball valves trying to dial it in again. Have an espresso and before you are finished with it you need to start again due to a bit of algae, a snail....

I guess all the above is assuming you are trying to have a quite return overflow? If you don't care about the gurgling and sucking noise you could ignore the above and a single pump would work.

Great point. Fine tuning overflow, that's something I haven't thought of. Thanks.

As far as your balancing goes. Just install a gate valve in the shortest linear length pipe. If one pipe run is closer to your first tank, most of the water will go that direction. Just add a gate to throttle flow and divert more to the longer run

I'd say the distances between the two tanks from the return section are quite similar.

 

[Levinson]

Thanks for your replies. I think I have narrowed down my options enough.
Though I won't be buying them right away as there are also other things I need to buy and I want on buying them all at once.