The Dolphin 3 is pressure-rated and quiet. Problem is that it moves about 4500gph and consumes aroung 850watts! A more sensible alternative, or so i hear (no pun intended), is the GRI. It's supposed to be a very good pump...pressure-rated, low on energy consumption, and quiet. Go to Champion Lighitng and pull up the stat sheet on pumps. It has some pretty good info except that it lacks decible ratings.
Here are some of my experiences: I own and run a Mak 4. Love the thing. Low amp and energy draw, pressure-rated but a little noisy.
I also have an Iwaki 40, Japanese and pressure-rated. It's a <little> quieter than the Mak-4 but it's still loud. The difference in noise is practically insingnificant! Although i've had my Mak 4 running for only a year, i think the Japanese Iwaki is a lot longer lasting. A lot of my friends have Iwakis 5 years and older still running strong!
One of the best LARGE pumps i've had experience with is the Sweetwater pump distrubuted by Aquatic Ecosystems. The thing pumps tons of water, is a pennypincher on electricty (especially compared to any Dolphin!), and are freaking durable.
In my humble opinion, the best three pumps out there with the most bang for your bucks are, in no particular order, the Mak 4, the Sweetwater pump, and the Sen 900 pump.
Their flaws:
Mak 4 is loud but what do you expext for a pump that pumps 1190gp @4ft of head, is pressure-rated and around 165 bucks?
Sweetwater pump gph::electricity consumption is even better than the Mak 4 but the Sweetwater pump is not pressure rated and at 3500+ gph it's only suitable for large tanks. The pump is a pretty blue color, though
SEN 900 is perhaps one of the best pumps since bread and butter for its price. It pumps against a good amount of head, is fairly quiet and cool running BUT it is big as heck. This pump takes up half of a ten gallon tank. Good thing that the intake grid can be taken out to make it a third smaller. Even after that, pretty big though.
I have a pretty good feeling that the GRI is a very good pump. At that price, i have yet to purchase one though. It also looks as if the middle model is the best bargain as the third one consumes almost twice as much electricity and only gives about 20% more on gph's.
Well, that's my take on pumps based on experience. Hope you find it helpful.
JOHNNY
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