Conservation of Energy

[redfishbluefish]

I’m having second thoughts about my Valentine’s gift I just bought myself. (What can I say, I love myself! ) Anyway, I just bought an SWC 160 xtreme cone skimmer. What scares me are the posts I’m now reading about the pump….the Atman 2500….and the problems with the mesh wheel impeller. I’m wondering if my worries are real and if I made a smart purchase???

What drove this purchase is an attempt to save some energy. I’m currently running an MRC 3 with a MAG 24 that sucks up 265 watts of energy. The SWC is rated for 27 watts…..about 1/10 the power usage. Wooohooo!

Now don’t get me wrong, I’m extremely happy with my MRC and the amount of gunk this thing pulls out. These are extremely well made skimmers that can’t be beat on large tanks. With these new cones out, these “old-style” skimmers have unfairly fallen out of favor. What only bothered me was the amount of electricity it takes to run this beast. I’m just hoping this new-fangled cone skimmer can pull the same amount of gunk without giving me headaches over pump problems.

 

[mnat]

I have the swc 120 and love it. I think magic has the 160 and I believe there are more people out there with them. You might have to buy a heater though.

 

[downbeach]

Both George (TanksNStuff) and Mike (Mike S) have the Bubble Magnus NAC 7 with uses the Atman 2500, and both seem very satisfied with it.

 

[TanksNStuff]

Yep, my BM NAC7 cone uses that pump and I couldn't be happier. I can set mine up after my weekly cup cleaning maintenance and have foamy bubbles within 5 minutes of starting the pump... and making brown/green skimmate within 30 minutes.

If that thing works like mine, you'll love the SWC, which is almost the exact same design.

 

[redfishbluefish]

If I’m not mistaken, the Atman 2500 on the BM uses the pinwheel while the Atman on the SWC has a custom mesh wheel, and it’s this mesh wheel that has been the cause of snapped impellers.

 

[Mike S]

Hmmm I think my nac7 has a needle wheel impeler not the mesh wheel. I should probably double check in case I need to get a spare. You can get a needle wheel impelled for that motor if it goes.

I've been running mine for 3 months and so far no issues. I am concerned that it might be undersized for my tank down there road when my tank gets more populated. I'm happy with it so far but this is coming from a newbie who last bought a skimmer 15 years ago that was 5 feet tall.

 

[TanksNStuff]

I've taken my pump apart several times to check/clean the impeller due to all the issues I've heard about. I can say for sure that mine uses the mesh wheel and it looks like this:

I'd be interested in trying the needle-wheel impeller for it though, just to compare the difference in performance.

 

[Mike S]

I've only had mine apart once but I could have sworn it was a needle wheel. Maybe I'm having a senior moment at 40 lol. I'm due for a cleaning so ill report back what I have. I'm not sure if I am allowed to post commercial links but there is a store in CA that sells a needle wheel for that pump. Google should get you to them.

 

[Mike S]

I just pulled it apart. Definitely a needle wheel.

 

[redfishbluefish]

Well this is most interesting. Both Mike and George have a BM NAC7, but one has a needle wheel and the other has a mesh wheel. I thought I read that BM came with a needle wheel….George, did you buy your skimmer new or could the previous own have mod’ed the skimmer with this mesh wheel?


And by the way, here is what my mesh wheel looks like in my Atman:

And the other thought I now have is whose mesh wheel is better? What does BM show as far as a replacement impeller?

One more note; what I read is that the mesh modification gives you many more smaller bubbles, thereby increasing the efficiency of the skimmer. If you go back to a needle wheel, you supposedly get fewer and bigger bubbles. Just what I’ve read.

 

[Mike S]

It may just be a function of when we bought them. I just picked up mine in November. At the time i thought they came with mesh wheels and was expecting a spare. I was surprised it was a needle wheel.

The place that carries the needle wheel replacement says the mesh wheel is no longer available due to reliability issues.

 

[Nickjr000]

I have the swc 250a cone, it is sweet!

 

[downbeach]

I have a BM NAC 9, with an Atman ph4000 that has a pinwheel.

 

[redfishbluefish]

OK, now back to those of us who have the Atman 2500…..I’ve read a bunch of posts and let me summarize my findings.

I actually now have three impellers, and upon very close inspection, found that two are exactly alike, and one is slightly different. The slightly different one has an oh-so-slightly larger mesh wheel. Interestingly, when installed in the pump, the wheel has plenty of space to the outer housing. So I don’t understand why they say the mesh wheel is a problem on start up (implying that it was rubbing.) I also don’t know why this one is slightly larger??

The other difference is on the back-side of the magnet. Two of the impellers have a raise portion that would make contact with the rubber tit, while the other one has a depression. I’m not sure if the rubber tit contacts the impeller or, because of the depression, it directly contacts the pump housing.

Anyway, one of the recommendations I read to improve pump performance was to install a washer on the back-side of the impeller. The first impeller I’ll be using is the one with the depression on the back of the magnet. With this one, I’ve installed two #10 nylon washers (found at HD in Hardware in the drawers.) When I change out the impeller for one of the “raised” ones, I plan on using one washer.

I’m going to see if I can switch out my skimmer today.

 

[TanksNStuff]

It may just be a function of when we bought them. I just picked up mine in November. At the time i thought they came with mesh wheels and was expecting a spare. I was surprised it was a needle wheel.

The place that carries the needle wheel replacement says the mesh wheel is no longer available due to reliability issues.

I think that's it. Depending on when you bought them, it will have different impellers. Keep in mind that BM doesn't make the Atman pumps, they just buy them and use them on their skimmer.

I bought mine brand new, but it was over a year ago, so I likely have the old style.

Yes, the pump is/was available with 3 different impellers - mesh, needle and pin wheels. Also, there is apparently 2 different styles of the mesh wheel too.

Here's the pinwheel, along side the original mesh wheel

Here's the needle wheel (which looks kind of like Pauls mesh wheel)

Lot's of different choices available for this pump.

Paul, my pump got stuck from starting once. That was when I began my routine maintenance and cleaning the impeller every couple months. I'm not sure if it was stuck due to the mesh wheel or just because there was some buildup around the magnet shaft. But it worked fine after cleaning. Looking at the photos of the mesh wheels, I can see how the mesh strands sticking out could somehow get get jammed up on something and prevent it from starting. I think your washer idea may be a solution to preventing this... by making the wheel stand off of the shaft hole a bit more.

Let us know what you think after you hook it up.

 

[AqOb]

You are correct. It isn't the pump, but the impeller. I have yet to see a swc160 that will restart after even a 1/2 a second power loss. It is a wonderful skimmer, but everytime you lose power or unplug it you need to lift the skimmer out of the water till the impeller spins. I currently work on few tanks that have them, and you should really just get the swc 180 or a different impeller.

 

[trivan]

you need to lift the skimmer out of the water till the impeller spins.

I have the 120 and it is a very good skimmer, I'll have to remember this tip...

 

[Mike S]

After looking at the pictures that George posted it appears that i have the pin wheel impeler. I'm not sure where you are located but if you are near sj and want to try one in your pump to see if it works you are more that welcome to stop by. I can pull my impemler out of my Skimmer for you to try.

 

[redfishbluefish]

Mike, you’re too kind. I’m in Sayreville and I’m hoping I finally got this thing figured out.


Thank you AO for chiming in as well. Your response got me back to playing with this thing and hopefully finding one of the three Atman pumps that works. When trying your suggestion of lifting the skimmer out of the water, I was able to get the pump to start to produce bubbles. But, as I lowered the skimmer back into the sump, at about 7 ½ inches of water, the bubble column would collapse. I did this multiple times and it always failed.

Even though I do believe the modified mesh wheel is problematic, I also think I have a pump problem. I changed out the pump and now put three nylon washers on the impeller side, and it now appears to be working (for the past three hours anyway.)

Thanks again folks.

 

[TanksNStuff]

Paul that's great! If raising it makes it perform better, maybe you can build a short stand out of egg crate or PVC pipe?