Pond Boss Forums AERATION Systems questions Pump suggestions

I've got a weird situation. My neighborhood has a long narrow water feature, about 250 feet long. Starts with a waterfall on one end, and water runs through a couple of pools and rock beds to a larger pool at the end of the feature.

It used to be powered by an external pump. I found the old pump house in some bushes near the large pool at the end, but the box is now empty except for some electrical. It appears that at some point the external pump was replaced by a submerged pump. Fortunately, the data sheet on the submerged pump was sitting in the pump house.

It is a CentriPro Model 6M071, single phase pump, 7.5 HP and consumes 36 amps at 230 volts! That's 8.28 kWh. In other words, this pump is a massive energy hog. We run it 24 hours per day and it's costing us about $700 per month to run.

Based on very limited research, it looks like we could get an external pump with comparable HP that runs on less than half the juice.

My question is, do we really need a 7.5 HP pump? I'm not sure how many GPM we need. The waterfall is a cascade maybe 8 feet wide, so it's a fair amount of water, but it's mainly being pumped horizontally. Probably 250-300 feet horizontal, and maybe only 6 feet vertical.

Does 7.5 HP sound right?

That is a really big pump. What is the size of the output and GPM?

Ours is a 5 foot wide top rock for our water fall and we run 40,000 - 10,000 gph over it and it is lots.

Defiantly get a magnetic drive pump. We have two of these bad boys running ours. Don't notice them on the hydro bill.

Cheers Don.

FWIW I just read this morning that typical waterfall flow chosen by most folks is 1500 to 2000 GPH per foot of discharge. So for 8 feet you would be talking 12000 to 16000 GPH.

Thanks. I agree - it looks like I probably need about 12,000 GPH for the waterfall. I'm reading that Dynamic Head is measured at about 1 foot for every 10 horizontal feet, plus the static head. So at 300 feet horizontal plus maybe 6 feet vertical, that's 36 feet of DH?

Another site I read says that for a 3" pipe (which I think is what we have), I'd be looking at DH of about 30 feet.

So anyway, it sounds like I need about 12,000 GPH at somewhere between 30-36 feet DH.

Looks like the Sequence Titan 18000 GPH would work well. Data sheet says 12k GPH at 30' DH, and 10k GPH at 35' DH, and it only uses about 2-2.5kWh! That would save us $400-$500 per month in electric, meaning the pump would pay for itself in 6 months or less.

Is this pump the titan a brushless pump? I have changed all our pumps to brushless all but one and thats happening this spring. Two pumps were $30 per month in hydro and now don't notice the cost.