UPDATE 1/17/01: A number of folks wrote in with some good information:
- Bruce Paine found this pump for $34 at That Pet Place.
- From Tom Meeks: “Just a quick heads up on these pumps. I grabbed one as well (though at an earlier time and a higher rating — 300 gph) and it turns out the O-ring they use are not quite water tight, at least mine wasn’t. Basically, mine required an outside solution — like RTV instant gasket — to get a watertight seal.”
- Nathan Brown sent in an link to an article at Pro Cooling showing his fix for air leakage HERE that is similiar to what Tom did.
- From Areg Ashoghian: “How much pressure is good? I bought this same pump last year and explained the usage to the salesman at the time. He said if I change the size of the fittings that I would ruin the pump. The mag pump will over heat and die a early death. He suggested I use 1/2 fittings and that’s what I have
done.” (ED NOTE: Without any moving parts except the impeller driven by magnets, I’m hard pressed to see how it could fail.)
- From Glenn Stanfield: “In your review you failed to note if the 1/2” tubing was measured I.D. (Inner Diameter) or O.D. (Outer…) [ED NOTE: 1/2″ Inside Diameter]. I bring this up because most water (fluid?) connections are based on the N.P.T. (National Pipe Thread) standard, which is based on the I.D. of the pipe, and is a tapered thread. Hence, a 1/2″ NPT is actually about 3/4″. In fact, my 1/8″ NPT tap is nearly 3/8″ in measurement. The difference is in the open I.D. of the pipe, plus the pipe thickness and add in a tapered thread.”
- From Troy: “Use a cheap $5.00 Silva compass to see if the field is extending too far. Although the compass will be affected by everything close by, you should easily be able to see how far the field extends by bringing the compass close to the pump when it is on. If the needle changes direction, that’s how far the field extends.”
Good idea! I tried it and found a weak magnetic field extending to about two feet from the pump. I also tried it with my EHEIM 1046 and found it to extend only about 6 inches. The EHEIM is rated at 5 watts compared to the Pondmaster’s 25 watts, so I think that’s a clue to how far and strong the field will be. After a year of use, I have not had any problems or ill effects with the EHEIM.
- From Dan Moeller: “One thing you may want to mention in the review just for those who don’t already know, is that brass is a much better material to buy connectors and fittings in, since it’s self-sealing. I used to fill oxygen tanks and the same principle applies as far as sealing and leakage. They had VERY high pressure, and they had to seal well enough to prevent any leaking at all. No grease or teflon tape were used. Just slap the brass fittings together and snug ’em up with a wrench.”
Thanks to all who wrote in – adds a lot!
SUMMARY 1/16/01: Unfortunately now “Out of Stock”, this $13.32 (orig. price: $53.29) waterpump was a steal – I measured its output with 1/2″ tubing at 150 gph, more than enough for any watercooling system.
I posted a link to Petopia about a week ago and it looks like a number of folks cleaned out the stock they had; I doubt we will see this price again. I’ve seen it on other sites for around $50.
Even though the horse is out of the barn, I tried one out to see how it performs. If you’re thinking of getting a high-flow water pump, what I found should be applicable to others.
This is a Mag-Drive unit – the shaft is driven by a magnetic field; no seals to wear out. It can be used as an in-line unit which is how I tested it out. It draws 25 watts, so if you were to use it submerged, it’s going to add some heat to the water.
I ran the unit for a couple of hours and observed:
- NOISE: Not exactly quiet bot not noisy; more like a low-frequency hum. Placing it on a slab of foam is a must to isolate this hum from resonating with the case.
- WATER FLOW: I measured it at 150 gph with 1/2″ tubing.
- PRESSURE: I don’t have a means to measure this, but from the force of water coming out of the discharge end, it’s more than what you would see with a unit in the 60 gph range.
- LEAKAGE: At first, I did have “bubble” noise – an indication that air is entering the system someplace. I then used Teflon Tape (available at any hardware store) that plumbers use to seal pipe threads on the fittings and it disappeared. Air infiltration is much more likely to be at the pump’s intake side.
- HEAT: After a couple of hours running, it was barely warm to the touch.
One thing you wonder about with Mag-Drive units is how far the pump’s magnetic field extends out. To test this, I placed a floppy with next to it for an hour and checked to see of the data was corrupted. No problem. Even so, I would make sure to mount the unit as far away from hard drives as possible.
One other point: The unit is advertised at having 1/2″ fittings – not so. It has 3/4″ fittings. In addition to the pump’s cost, you will have to buy some step-down fittings to accommodate 1/2″ or 3/8″ tubing. A couple of examples are pictured above – not expensive, typically about $2 per – Home Depot has tons of these in plastic and brass.
In sum, my only reservation about this unit is pressure – it’s a lot more than what you’ll see with a 50-75 gph unit. All fittings must be well clamped and you must use Teflon Tape to seal the threads of any fittings. More noisy than the EHEIM 1046 (silent), if it’s sold again for $13.32, well worth it (comes with a one year warranty).