Backyard Aquaponics
A place to discuss aquaponics

crsublette found a link to the Eco Blue Pumps.

I've been in touch with one of their distributors and got some performance data on three of their pumps, the Eco Blue 320, 500 and the 900.

At first glance they look pretty cool because they are variable speed pumps.

First concern though is that in the overall specs they are given a 90% or higher efficiency rating. Needless to say I find that hard to believe because efficiency varies depending on head, power draw and flow. Giving an overall figure doesn't make any sense. They could be referring to maximum efficiency but even if they are 90%+ is literally unbelievable and the data supplied tells a different story.

They have plotted the data in a rather unconventional manner so you have to get your head around the graphs


From the data supplied the efficiency for all pumps at 0m head is almost always below 0.1% ie 1/10th of one percent at wattages above about 100W more like less than 0.05%.

From the data supplied the peak efficiency of the three pumps is:

Eco blue 320 31% efficency while drawing 220w at 2m head producing 12.5m3/hr
Eco Blue 500 44% efficiency while drawing 200W at 2m head producing 16m3/hr
Eco Blue 900 41% efficiency while drawing 600-900w at 5m head producing 18-27m3/hr

The result for the last pump is a bit concerning because it is unusual to have a pump capable of maintaing a constant efficiency rating over such a wide range of duties. Also bear in mind that we only have data on 3 head heights for each pump. There very well may be a higher efficiency achieved between head of 2m and 5m all of the pumps and possible higher efficiencies for the EB 900 at heads above 5m.

Even though these pumps do not have a higher efficiency rating than the Laguna's they could be a more efficient pump because they come with variable speed controllers. You would have the option of turning down the flow when your fish are small and turning it up as they grow. So even though mechanically they are not as efficient operationally they could be much more efficient.

Some of the controllers are programmable which would also be very useful.

The problem though is even if they perform as well as mostly described at about $900 a pop I don't see myself getting one.

I'm afraid I turned off those pumps pretty quickly when I read some of the blurb:

"...filtering 35,000 gallon pools to crystal clarity on just 150 watts per hour".

Watts per hour is meaningless. Watts is already a rate- joules per second, adding per hour on the end is just nonsense.

They need someoone who knows what they are talking about to write this stuff.

Then we have:
"Besides that, they are environmental friendly and good for CO2 reduction. "
and
"...True Sine Wave technology for the best features: high efficiency (90%), noise free running, high torque, wide RPM range, CO2 reduction."

CO2 reduction? These pumps must take CO2 out of the air and sequester it- amazing!

Just keep them away from my beer!

And as Stuart pointed out:

"high efficiency (90%)"

Extremely unlikely.

I'm not sure I get your drift, I guess that sort of depends on what you're trying to do with it and what they are trying to get across Power company seems to think it's useful with Kilowatt hours and it might be helpful to figure how much the pump adds to your power bill . Just thinking that might be what they were trying to get at.

Not unlikely, unbelievable even if the accompanying flow curve supported such a claim. They are made in China so I think some of the their promotional material might suffer a wee bit in translation.

It also shows the issue of scale again for those of a commercial mind set.

A pump I'm looking at the moment is getting than better than 70% efficiency from ~3m head producing 75m3/hr to ~1.75m head producing 140m3/hr.

That is a lot of flow but its the smallest industrial efficient pump I've found to date. Only costs about about $1300 for a bare pump (without motor). Motors don't cost a lot so the overall cost is pretty minor compared to the money required for equivalent pond pumps.

The next size up costs $700 more @ ~$2000 but on its lowest documented speed setting of 900rpm its producing over 225m3/hr @ ~5m head to 300m3/hr @ 4m head with above 80% efficiency.

It's all about the units, it is just plain incorrect to say watts per hour in this context. A watt is a rate of power use, which is what they mean, a Watt hour is an amount of energy - power X (not divided by!) time. What happens after 2 hours of 150watts per hour, is it then 300W, and after 10 hours is it 1.5kW? I dont think I need that much pumping power

The pump consumes 150W power. The pump consumes 150Wh of energy per hour

"watts per hour" is a common mistake people make when they mean "watt"- but a pump manufacturer should know better! it is just high school physics.

Ah I see what you were getting at

Not just pump manufacturers.

I had yet another pump distributor have the same issue plus they tried to tell me that by using too big a pipe I would reduce the flow.

Buuut Stuart! if you use a big pipe you have all that extra weight of water pressing down on the pump.

I know Gordon uses a variable speed DC motor, but I have my doubts that centrifugal pump impellers can do multiple duty with efficiently (unless there has been significant changes in design). In the past quality pump manufacturers eg Iwaki offered different impellers for different duties. So what has changed?

Maybe nothing.

The industrial pumps I was talking about above are mixed flow pumps which are sort like an axial flow pump but quite a bit different. More like an axial flow than a centrifugal though.

you could, try fitting that pump to a council sewerage pipe and tell me ytour flow is outstanding.

also, 725 pound for the cheapest one is a tad expensive.

Thanks. I appreciate the analysis!!

Yeah, the guy emailed me, but forgot to include the hyperlink for the flow chart.




For me, with shipping cost and taxes... the 320W unit would be $895.00...

For a small aquaponics system... yeah... that's a crazy high price...

Awesome... if I wanted to do 37,000gph at 1.75m head... lol...

Old Faithful geyser in my aquaponic system would be an interesting marketing twist to get people to buy some vegetables....


BTW Stuart... Mr. Van der Werf says hi..

Well then... the search continues...

I am getting disappointed in my koi connoisseur buddies... they seem to know diddly about pumps... Blue Eco was one of their recommendations...

I really appreciate this.

Hey Stuart, do you have a system build thread?

I enjoy reading them... always something to learn... definitely quite interested... figure by now, after 8+ years, you'd have a few really interesting ones...

Give it a rest everyone