# Is it possible to Remagnetize an Eheim Impeller?



## kyle2088 (Jun 28, 2005)

Is it possible to Remagnetize an Eheim Impeller?

I have been a long user of eheim filters for last 20 years and love the products. Every 5 years or so they may become a bit noisey or flow becomes reduced and I end up replacing impellers or shafts and bushings which isn't bad but in my efforts to save money reduce waste I aim to achieve better. I have accumulated quite a few old impellers and was wondering if it is possible to remagetize the impellers instead of throwing them in the dump

3 of the options I was thinking of are as follows;

1) to add a small but strong magnet Circular with a whole in the middle to fit on top or bottom of the existing magnet

2) Use a strong magnet and run it along the side of the existing impeller to recharge the magnet strength.

3) Create a new magnet and reinsert the shaft impeller sleeve into it using a stach of circular magents with holes inthe center

There are a number of rare earth magnets very small and very very strong .....on the market now that could possibly be used for the above methods.

I know people have experimented with eheim 2215 2217 and interchanged impelless and that some impelles are made and designed for N.America or Eurpoe specific...50hz or 60hz.

My question is do you think these ideas are possible or wise or it would be better to just spend the $25 every 5 years or so to replace the impeller. I realise that Eheim spends alot of money researching and engineering their equipment to perform its best just looking to save some cash and help out the environment.

Thx


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## TropTrea (Jan 10, 2014)

Re-Magnetize? Yes it is possible however I do not think purchasing the equipment would be cost effective unless your doing this on a regular bases. I would suspect the remagnitizing equipment would cost several hundred dollars. 

Constructing new Impellers with new magnets is possible but again you need almost the exact specifications as to the original Magnets. This is especially true so you do not get wobble on the shaft or anything binding. Considering the cost of there filters and the cost of replacing the impeller assembly I think it is good deal for $20.00 every 5 years. 

I have used other brand magnetic Drive pumps for many years as well. And I will say that trying to get around the replacement cost or reducing it is almost impossible. The motor and magnets are pretty much mach sets. A stronger magnet I found will often cause the shafts to either snap or bend. If it snaps your in luck you just have a pump that does not pump, if it bends it can become more expensive as when the impeller freezes up for a long time the "motor" can overheat and burn out. 

Note on some large pumps I have paid over $100 for an impeller but it beat the $400 or more for a new pump. Right now the biggest pump I have running is an 1800gph that has been running to pump the water from my sump in the basement to my tanks upstairs. It has run for 9 years now none stop except for power outages without being touched. The pumps that give me the most headaches are the bigger ones in the 3,500 plus rang that I use in the summer for the ponds.


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## kyle2088 (Jun 28, 2005)

Thank you for the response. It does make sense.

When I was younger I tried expermenting with aftermarket parts on my car. And unless you have enough money and time it is not worth it. Did the Cat Back exhause make my car go faster? Now there is no backpressure on the exhaust - how does that affect the way the engine runs? Lowering the car helped steering and cornering but how does that affcet the way the overall weight of the car is distributed putting more weight on other areas that maybe the car was not designed for.

Respectable companies poor a tonne of money into research and development into their products before they are released and contunie with updates and recalls when things go wrong or they find an improvement.

When you change something (however small you may think it is), it may have astounding negative impact on the overall life and performance of that product.

It appears in this caseo cutting corners is not worth it.


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## Darkcobra (Nov 23, 2009)

If you literally mean "remagnetize" (rather than replace due to physical damage):

That is achieved by heating the magnet in excess of its Curie temperature, which is about 450°C for ferrite magnets. Apply a strong external magnetic field, then allow to magnet to cool under its Curie temp with that field still in place, during which time the field will be "locked in" and permanent - at either the strength of the external field, or the limit of the ferrite material; whichever is lower.

Stronger neodymium magnets typically can't be used for the external field, as they have a lower Curie temp of 80°C - if heated to there, they become demagnetized. So an electromagnet is typically used instead.

The impeller magnet is likely a four-pole device, made of two individual magnets glued together. That cannot be re-established unless you also separate the halves, remagnetize them individually, then glue them back together.

Just in case you were curious about the process, regardless of feasibility.


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## TropTrea (Jan 10, 2014)

kyle2088 said:


> When I was younger I tried expermenting with aftermarket parts on my car. And unless you have enough money and time it is not worth it. Did the Cat Back exhause make my car go faster? Now there is no backpressure on the exhaust - how does that affect the way the engine runs? .


Less back pressure does increase performance at higher RPM's and the expense of creating less performance at lower RPM's. Same with Cam shafts longer duration gives you more more power at high rpms but causes the engine to sputter and stammer at lower Rpm.s Now you need to change the rear axle ratio to put the usable horsepower where you want it rather than 2 times the legal speed limit.

Yes those were the day Weekends at the drag strip. I doubled the horse power of my engine but it ran slower ET's until l I switched the Rear Axle ratio to 4.88. from the old 3.23. Gas millage went into the single digits then but it was under 40 cents per gallon for premium back then. Thought it a sign of the end of the world when gas hit 50 cents a gallon.

Yes change one thing and other thinks fall out of balance. I also ran itnt this on pond filteration systems. If a filter is rated for a max of 2,400gph it will not do the job when your feeding it with a 3,600 gph pump. And with the added back pressure on the pump the pump will not last as long either.


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## kyle2088 (Jun 28, 2005)

Thank you Troptree and Darkcobra for your expeiences and detailed information


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