A test of selected waterpumps – Joe
SUMMARY: System resistance takes a BIG toll in waterpump flow rates.

The good guys at Xoxide.com were nice enough to send a bunch of waterpumps to test out:
- Eheim 1048 – 10 watts
- Eheim 1250 – 28 watts
- Hydor L20 – 14 watts
- Hydor L30 – 23 watts
- Via Aqua 1300 – 28 watts
Eheim is a well known brand in watercooling circles, Hydor and Via Aqua less so. The Via Aqua is noteworthy for all its accessories:

I particularly like the ball valve with “fill tube” (upper left) – for a closed loop system, this greatly simplifies bleeding the system; this can also be done using the intake nipple shown as the bottom left. Considering its price is about half that of the others, the Via Aqua deserves a look.
I assembled two watercooling setups:
- High Resistance: Koolance CP-200G waterblock, Iceberg radiator (5/16″ ID tubing)
- Moderate Resistance: Twinned 5″ radiators with 7 loops total, BE Cooling copper waterblock (7/16″ ID tubing)
Each pump was fitted with supplied intake/outake nipples; the filters and filter housings were removed.
I then immersed each pump completely, ran each until all bubbles were cleared and then timed how long each took to fill a quart container (three times for each pump). The only difference was the pump – everything else remained the same for each pump. In addition to the pumps listed, I included a Beckett G150APCP (not a current model – 60 watts) – a centrifugal pump rated at 150 gph (the rest are mag-drives).
High Resistance
Pump |
Measured gph
|
Rated gph
|
Percent M/R
|
H Max ft
|
Hydor L30 |
34.5
|
320
|
11%
|
6.4
|
Beckett 150 |
32.6
|
150
|
22%
|
na
|
Via Aqua 1300 |
31.6
|
343
|
9%
|
5.7
|
Eheim 1250 |
31.1
|
317
|
10%
|
6.6
|
Hydor L20 |
26.1
|
185
|
14%
|
4.4
|
Eheim 1048 |
25.5
|
158
|
16%
|
4.9
|