Which pump

[tcyiu]

I am setting up a 60 gal tank with a sump. The sump is set up 1-2 ft below the tank. All told, there will be about 5ft of hose from the pump to the spray bar.

The question is: should I buy the Eheim 1250 (320GPH) or 1260 (630GPH)?

Kinda weird that there is nothing in between.

Because of the fittings that I inherited, the overflow will be plumbed with 1" ID hoses. That's a pretty big draining capacity. If I go with the 1260, will the fish get plastered against one wall because of the current?

Thanks?

Tim

[Chad Hughes]

Tim,

I'd go with the larger pump. With the head height, you'll not get the full function (GPH) that is stated on the pump. The current won't be as bad as you think and you can always trim it down. You can't trim up!

Best wishes!

[MSD]

The 1250 is a low power pump and is good for low flow rates if that's what you want. Slower flow can increase the water contact time in a wet/dry trickle tower and that will improve efficiency. It all depends what you are trying to achieve with your tank and sump. If the sump is just for greater water volume it doesn't matter which you use unless you want high flows. .

[tcyiu]

Thanks folks. The sump I intend to use will have room for 14 gallons of media. I don't think contact time will be the issue.

What is the optimum turnover rate within the tank? 3X? 5X?

My fear with the larger one will turn over the tank too much. Of course as avionics said, this could be trimmed down.

The much lower power usage of the smaller one is very attractive.

Tim

[Chad Hughes]

Tim,

I'd go with a minimum of 3X turnover.

What is the wattage difference between the pumps? Just curious.

Best wishes!

[tcyiu]

From the Marine Depot website:

1250 317gph 28W
1260 635gph 65W

Weird. No product in between.

Tim

[Chad Hughes]

Tim,

Yes, that is a bit of a jump. The larger pump will cost you 47.45 Kwh per month running 24 hours a day. Depending on what part of the country you are in, you may not even notice it on your electric bill.

I'd honestly go with the bigger pump.

Best wishes!

[Dkarc@Aol.com]

What you need to look at is a pump curve for the specific pumps you are looking at. Here is a link to both of those specific pump curves:
http://www.marinedepot.com/ps_AquariumPage~PageAlias~pumps_eheim_universal_ho bby_powerheads_information.html
5ft of hose length which we can equate to roughly 5ft of total head height (or known as "head"). Misc fittings and spray bar will add probably another foot of head to the equation to give us around 6ft of Total Dynamic Head (TDH). If we look at the upper pump curve chat (yellow line) we can look on the left to the TDH of 6ft and follow that over till it intersects the 1250 pump curve. The Eheim 1250 at 6ft of pump head will give you 79GPH. 1x turnover per hour......no dice for that pump.

The Eheim 1260 pump curve chart is below the first chart. The 1260 is more "pressure" rated compared to the 1250 and because of that we can use a slightly higher TDH against it to get the flow rate we need. At 6ft of TDH it'll pump around 450-500GPH which is more than enough for your needs. Put a ball valve on the output side of the pump and you can cut it back a little bit if the flow is a bit much (but no more than 30-40%, some pumps can become damaged long term if throttled back excessively and operated as such).

So as stated earlier in this thread, the 1260 is gonna be your better bet.

-Ryan

[tcyiu]

What you need to look at is a pump curve for the specific pumps you are looking at. Here is a link to both of those specific pump curves:

...

-Ryan

Thanks Ryan. Very cool charts. I always thought "head" referred to the vertical distance, vs the total length of hose. In my case, the water would need to be lifted 2 ft, so I thought I was OK. I guess I was wrong. BTW, does anyone know why the 1260 and 1262's charts are linear?

Chad, glad you looked at it from a KWh standpoint. That prompted me to go look up our rates. Our utility's website was very confusing, but at the end, I think the average is 0.23/KWh. So it would end up costing $6 more a month. Plus the extra $50 up front for the larger pump.

I think what I'll do is to re-arrange the placement of the filter and get the total head down to around 4ft. It seems the largest drop-off in flow for the 1250 is between 4 and 5ft. Then I can run the 28 watts and not feel guilty.

Sigh. I went and got a Prius so I won't feel so guilty driving around. That's partly why I'm stressing out over these measly 65 vs 28 watts.

Gosh darn it.

Tim

[Dkarc@Aol.com]

Thanks Ryan. Very cool charts. I always thought "head" referred to the vertical distance, vs the total length of hose. In my case, the water would need to be lifted 2 ft, so I thought I was OK. I guess I was wrong. BTW, does anyone know why the 1260 and 1262's charts are linear?

Chad, glad you looked at it from a KWh standpoint. That prompted me to go look up our rates. Our utility's website was very confusing, but at the end, I think the average is 0.23/KWh. So it would end up costing $6 more a month. Plus the extra $50 up front for the larger pump.

I think what I'll do is to re-arrange the placement of the filter and get the total head down to around 4ft. It seems the largest drop-off in flow for the 1250 is between 4 and 5ft. Then I can run the 28 watts and not feel guilty.

Sigh. I went and got a Prius so I won't feel so guilty driving around. That's partly why I'm stressing out over these measly 65 vs 28 watts.

Gosh darn it.

Tim

Head is still a reference of vertical head/pressure on the pump, but there are other aspects of the plumbing which add to the head and that total is known as the Total Dynamic Head (TDH). Flow restriction from friction/sheer within the return plumbing, fittings (90's, 45's, ball valves, etc) is what's added together to the vertical head to determine the TDH. On a small system like yours flow restriction through the piping is of no concern but for ease of math, every 90 that is added to the return plumbing will add roughly 1 ft of additional head (or more if the pipe is undersized for the flow). A ball valve adds a little less than half a foot of head, same for a 45. There is a lot to take into consideration when sizing pumps for a system.

-Ryan

[Darrell Ward]

I have a 125gal. running a 1260 in the sump under the cabinet. It's plumbed with a check valve, 1" tee, and split into 2 -1" returns with vinyl hose. It works fine, plenty of flow, never an issue with it in 2 years. This pump replaced an external that I considered too noisy. If you find it has too much flow for your setup, just install a ball valve in the return and throttle it back. 28 vs 65 watts is nothing. Don't sweat it. You won't even notice the difference. I'm planning a new fish house, with heat and air systems, etc. Talk about an increase in electric usage!

[tcyiu]

Sorry, I've been away for a while.

I bit the bullet and bought the 1260. MAN that thing moves water in a big way. Too much for my 1"ID oveflow system. I'll get a ball valve when I get a chance and see if I can "balance" the system.

Thanks again.

Tim

[asiong]

Yeah, already mentioned, but the larger pump is the way to go and controlling the flow with a ball valve . . . good choice! :D