# Hydor Koralia Powerhead.



## Eskobar (May 28, 2006)

Does anyone have experience with these Hydror Powerheads that are heald on with magnets? I have an unusual amount of pooo adding up at the bottom of my tank and wanted to add a couple pumps.










1) How strong is the magnet?

2) After some time if I move around the pumps, does the magnet get weaker?

3) how do the impellers and shafts hold up with sand?

Thanks... :thumb:


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## prov356 (Sep 20, 2006)

1) Very strong. I'm using them on 1/2" thick acrylic.

2) I wouldn't think so, but haven't moved mine around a lot. I know if you just stick the magnets together as it comes out of the box, they're not easy to get apart.

3) Mine aren't subjected to sand, but they should hold up fine. Think of an outboard motor on a boat. The sand would get kicked out. There's no where for it to clog like with a regular power head that draws water through a tube.


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## cjacob316 (Dec 4, 2008)

all magnets loose power but the pump will die first lol, actually you might die first


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## Eskobar (May 28, 2006)

Awsome thanks sound like I pick one up....


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## NetStalker (Oct 9, 2009)

I was having problems with poo gathering under the rocks, Wife picked one of these up for my 135 tall acrylic and WOW what a difference. Quiet, moves all the poo over to the opposite corner and gathers in one area, makes it a snap to vacuum. As an added benifit, its like all my cichlids have gone to LA fitness, they are playing in the current and wearing themselves out instead of fighting each other. I have cross members on the top of my tank so I top mounted it in the corner and its hardly noticeable. Magnets work great, but they dont float very well....ahh, thats another story altogether...

Regards,

NS

:fish:


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## noddy (Nov 20, 2006)

I have a #4 on a glass tank that is 3/8" thick. It wouldn't hold on one of my other tanks that is 1/2" glass, and that's brand new out of the box.


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## larry.beck (Jul 31, 2009)

Does anybody know if they'll hold on 3/4" acrylic?


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## KaiserSousay (Nov 2, 2008)

cjacob316 said:


> all magnets loose power but the pump will die first lol, actually you might die first


 :lol: :lol: :lol:


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## prov356 (Sep 20, 2006)

larry.beck said:


> Does anybody know if they'll hold on 3/4" acrylic?


I can test it tonight. I'll post back if you haven't gotten an answer by then.


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## NetStalker (Oct 9, 2009)

larry.beck said:


> Does anybody know if they'll hold on 3/4" acrylic?


At work, but just had the wife measure the acrylic on our tank at home and she says its 5/8 on the section we have the unit mounted, and its a #4 as well.

it has a pretty good grip on 5/8" I cant imagine another 1/8" causing a lot of issues.


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## prov356 (Sep 20, 2006)

I just pulled my koralia #4 from my water storage tank and tested it out. When pulling it, I discovered that it actually has a suction pad that goes up against the inside of the tank to help hold it. When I pulled the magnet, I expected it to fall to the tank floor, but it didn't move. I had trouble pulling it off. It's even got one of those little pull tabs that help you undo the suction like some suction cups have. So, it's not just the magnet that holds it. The suction pad actually does more than the magnet to keep it attached. When I tested with 3/4, it didn't hold until I pushed it against the piece so the suction pad would take hold. Then it held fine even without the magnet. The magnet alone wasn't enough to hold it on the 3/4". It was enough for 3/8" And I used acrylic for testing. Like lumber sizes 3/8 isn't really 3/8 and 3/4 isn't really 3/4. They're slightly under. Not sure if glass goes the same way.

HTH


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## larry.beck (Jul 31, 2009)

prov356 said:


> When I tested with 3/4, it didn't hold until I pushed it against the piece so the suction pad would take hold. Then it held fine even without the magnet. The magnet alone wasn't enough to hold it on the 3/4".


Interesting. Do you think it was holding well enough to actually run in that position? We were talking about the Vortech propeller pumps in another thread and as much as I love the design, I just can't see putting that kind of money into a circulation system on a freshwater tank. Plus I question how well they work on thicker tanks as well, since they're relying on magnetics not only for the attachment point but for the motor-to-propeller motion!



NetStalker said:


> it has a pretty good grip on 5/8" I cant imagine another 1/8" causing a lot of issues.


Cool. Any chance it's the suction cup holding it as Tim mentioned about his experience?


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## prov356 (Sep 20, 2006)

> Do you think it was holding well enough to actually run in that position?


Yes. If they attach even with the suction pad alone, then they'd run fine.



> Plus I question how well they work on thicker tanks as well, since they're relying on magnetics not only for the attachment point but for the motor-to-propeller motion!


I don't understand this. The attachment magnet and any 'drive' magnet are two different things. How does one affect the other? :-?


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## Number6 (Mar 13, 2003)

larry.beck said:


> Plus I question how well they work on thicker tanks as well, since they're relying on magnetics not only for the attachment point but for the motor-to-propeller motion!


 Koralias do not have the external drive... that's the much more expensive ones like Tunze. The power cord runs into the aquarium... that's where the drive is located as well.

Koralias are fantastic little water pushers and will stick in place most of the time without the magnet, but 100% of the time with the magnet in place. It grips through glass or acrylic quite well and 5/8" won't be a problem on any of the bigger Koralias. Can't speak much on the little ones under 3, but 4 and up into the magnum sizes shouldn't budge.


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## Geddonight (Aug 7, 2009)

The suction cup aspect of the Koralia is what keeps it in place. From my issues with suction cups on heaters, etc. is that they tend to pull away easier later in life as they stiffen and weight bears upon them. The magnet tends to help counterbalance the weight of the powerhead itself, so that less strain is on the suction cup. (Well, it makes sense anyway--I'm no engineer)

I really like my Hydors. I'm gonna order a few more for my tanks.

The only thing I dislike is one tank has an ultrafine aragonite which stays stirred up to some extent. Rather frustrating to have little white specks all the time.

When we move, that's getting changed to pool filter sand :thumb:


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## larry.beck (Jul 31, 2009)

prov356 said:


> I don't understand this. The attachment magnet and any 'drive' magnet are two different things. How does one affect the other? :-?





Number6 said:


> Koralias do not have the external drive... that's the much more expensive ones like Tunze. The power cord runs into the aquarium... that's where the drive is located as well.


Sorry guys, I obviously wasn't very clear. I was saying that I'd love to go with Vortech's but wonder how well they'd work with the thicker 3/4" acrylic tanks. I understand that the Koralia's don't use that model.

Based on the great feedback, though, I think I'm going to test one out on my tank. Do you guys put your water supply down low in the tank and use the Koralia at the top, or the other way around? I'm specifically looking to get more of the fish waste moved over closer to my canister intake.


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## Eskobar (May 28, 2006)

Seems like they hold well with the suction cups built into the magnet.

THNX guys :thumb:


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## prov356 (Sep 20, 2006)

> Do you guys put your water supply down low in the tank and use the Koralia at the top, or the other way around?


I use mine at the top for some surface ripple.


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## FishyFishy! (Dec 2, 2009)

I would also like more input as well about the placement. I have a 66 Gallon that has a fairly weak Eheim spray bar. I would love some more circulation, as well as the previously stated idea of pushing the 'pooh' around into one area of the tank. What would you suggest? (Seeing as I have a random Koralia laying around..


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## prov356 (Sep 20, 2006)

> What would you suggest?


Experiment. Start in an upper corner and aim it a bit toward the surface and away from the side. It should push water to the front and then down the front of the tank and continue in a somewhat circular front to back current. But, it's adjusted easy, so just play around with the different directions and watch the floaties.


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## vealboy (Jul 27, 2009)

I have a Koralia 2 mounted on the side wall of my 55 gal, just about half way down, and have the head pointed upward, and slightly toward the front of the tank. It creates nice current, and the desired water rippling on the surface. It is also on the opposite side of the tank as my HOB intake. So the current moves water up and to the right.

But I will sometimes move it to the back wall, and point it upward toward the surface. I am thinking about moving it to the same side as my HOB output near the top of the tank, and pointing it downward and toward the back to see how that current looks, and how the fish react.

But, as Prov356 said, experiement.


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