Impellers

[george]

For anyone with a Euroreef or ASM skimmer with a Sedra pump (not sure if other skimmer manufacturers or pump makers would have a similar problem):

I recently noticed that my pump wasn't performing nearly as well and had to be "kick started" with air into the intake tube in order to produce foam in the skimmer. Otherwise, it just burbled. I took appart my pump and found not only high calcium buildup considering I'd just cleaned it recently, but a distended impeller magnet area. If you look at the photo, you'll see the bulge I found. Undoubtedly it produced more friction which would cause more buildup and potentially cause motor problems.

A new impeller (source is in the "where to find things" thread) was like getting a brand new skimmer. Apparently I hadn't noticed it for a while and now I had to jack my adjustment tube on my Euroreef way back down to not completely flood the collection cup.

Check your impellers regularly, especially if you bought your skimmer used.
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[broreefr]

I have a Euroreef skimmer and use sedra return pumps on my system, I will definately keep an eye on mine but so far they have been super reliable, from looking at the pic, I have to wonder if the damage may have come from the pump running dry. You mentioned used, if it was purchased from someone else you never would have known if they had accidently run the pump dry.

Just a thought

 

[glxtrix]

I ran into something kinda similar awhile back, a good monthly cleaning of impellers in vinegar will insure everything is running tip top

 

[george]

Quite true. I intend to dissect the impeller tomorrow and see if it's rubber causing the bulge or something underneath such as rust.

 

[cameron]

Thanks for the info. I am thinking about ditching the sedra on the ASM G3 I have now and switching to the OceanRunner 2700 since I noticed the 2700 produced a lot more bubbles than the Sedra. Maybe a new impeller will bring the sedra back to life.

 

[george]

Ok, follow up:

From my dissection, it's not the rubber, but the magnetic housing underneath. The impeller seems to have a magneted core made up of ferrite dust wrapped in what appears to be a thin layer of alluminum then wrapped in the outer rubber or plastic coating. Without smashing the impeller to bits and getting magnetic iron dust everywhere, I can't see what acutally caused the bulge in the impeller. I'd theorize that water finally got in and caused rust which caused the bulge.

I am suprised at this construction, but I hope there's an engineering reason for not having a solid magnet. Stronger? As cheap as magnets are, it can't be a cost savings to assemble this.

 

[justonemoretank]

I had a Sedra pump that did the same thing. Unfortunately I did not see the bulge until it was too late and it ruptured! Yes it was due to rust of the magnet. I bought a new impellar and it also died due to rust about a year later.
I have an ASM G4 skimmer with the Sedra pump and it seems to be fine as of today (knock on wood).
You could try the diy impellar upgrade that everyone is talking about with mesh if you are replacing the impellar or getting a new pump. I will have to try it someday when I get a chance. I love to tinker with the tank.

 

[cameron]

I have bought some of the Enkamat and will have lots left over. If anybody wants some to build the mesh wheel impellor, let me know and I will cut you off a bit.

 

[vettesarebest]

What is this about the Mesh Impeller?

 

[cameron]

The reefcentral guys are getting up to a 50% improvement in skimming with these new impellors. They basically cut the needles off the impellor and zip tie Enkamat to it.

Here are the instructions for using a 3M blue scrub pad:

1. Remove the impeller from pump.
2. While using the utility knife, cut each pin at the base of the impeller. Try to cut it flush with the disk.
Remove all pins.
3. Cut a square piece from the blue scrub pad. The square needs to be larger than the disk.
4. Stick the pencil directly in the center of the pad, use the pencil to create a hole that will allow the bearing to peek through the pad. Test fit the pad on the disk. The bearing should easily fit through the hole on pad.
5. With the pad on the disk, insert a zip tie from the back of the disk, thru the pad and back down thru the pad and finally thru the disk. There are 4 holes on the disk. You wil be using two zip ties to secure the pad to the disk. Make sure the male and female ends of the zip tie are behind the disk. When looking at the pad on the disk you should only see two zipties secured to the disk. The zip tie connection is behind the disk. This is important because if you make the connections in front of the disk on top of the pad, it will produce drag and less performance.
6. Make sure zip ties are tight.
7. Remove excessive zip tie material.
8. Trim pad to the same diameter as the disk.
9. Put impeller back into pump.

 

[justonemoretank]

I would like to try this but so far I have not had the courage. Maybe someday when I have a little time I will try it. I am just afraid that if it does not work I will have to hurry and order a new impellar and get it shipped next day!

 

[cameron]

Order a new impellor. When it comes in, fix up the old one. If it blows out or you screw up, you have a new impellor in your pump.

 

[mufret]

You could just order the normal impeller (which is quite a bit less) and mod it. That way you'll always have your original impeller in case things don't turn out.

 

[justonemoretank]

yes, yes... I know, I know. I really should do this and take lots of pictures and have it all documented. It might turn out really well.