Koralia water pump review

[crazy loaches]

I happened upon these while searching for some good circulation pumps for my new tank I'll be setting up for my clowns and freshwater fish. I looked at many, Seio, Tunze, and others. But the Koralia caught my eye and was the most reasonably priced. The openeness of the pump was a concern; adventurous Botia might be able to actually get inside the unit. But I figured I could make a screen to go over it so I went ahead and got a pair of Koralia 4's. After having them in the tank today I figure I'd right up a brief review seeing how they haven’t been talked about much here.

One of the first things I noticed is the specs on the box are different than what’s on the literature inside. That makes me wonder about their quality but I'll give em the benefit of the doubt.

Technical Data from sheet:
1200gph 8.5W (115V 60Hz)
4600l/h 11W (230-240V 50Hz)

On the box it says:
1200gph 12W (115V 60Hz)
4600l/h 11W (230-240V 50Hz)

FWIW other websites I have seen them advertised on have had even different specs yet, perhaps they have changed them once or twice and this is causing confusion, I dont know.

I took some pictures and compared it to the common Maxi-Jet, which I have several of. I used a MJ600 since I wasn’t using it, but the bigger MJ1200's also have the same identical housing. FWIW the MJ1200 is rated at 295gph and 20W. Here are the pics, click on them for 800 pixel wide versions.

Side view:



Front view:



Disassembled view of motor, note that the Koralia motor housing is smaller than the MJ in all dimensions:



Mounting, suction cups for the MJ and a magnetic holder for the Koralia:



Here are the impellers, MJ on left, and Koralia's propeller-like impeller on right. Note the permanent magnet is even smaller on the Koralia:



And finally, a view of the Koralia with the front piece aside:



My first impressions are very good. The design is very similar to the Tunze Turbelle Nano Streams (just from what I have heard and see on the net - I dont have one). I think it was the model 6045 that most similarly matched the Koralia4. But it costs double. I purchased the K4 from Drs Foster & Smith for $48. Even in my 75G which I am testing 1 out now the flow isn’t to severe for my plants or blowing substrate away (but I am not going to leave it in there long term). The flow seems to spread out a great deal, but still pushes water for a good distance. At about 4" the flow is less forceful on my hand than my Maxi-Jet 1200, but I am sure the volume of water its moving is much greater. I am wondering why they haven’t really used propeller shaped pumps before... they seem ridiculously more efficient. Then I thought, well up until recently most 'power heads' were specifically designed to work with UG filter tubes and such, and thus needed an intake that could be hooked to a tube. Well this one is more like a boat, with water being drawn in freely from all around the propeller and pushed out into the open unrestricted. The main part of the pump is about the size of my fist and is slotted all over for the intake. Placing 1 or two finger across the intake I cannot feel any suction, it takes 3 or 4 fingers wide for me to feel some suction. It would take a lot for this to clog, which is one of the problems I run into with my Maxi-Jets and plants. Even on my 75G the K4 isn’t too powerful, but I dont know if I would put one on a tank much smaller.

Noise is uncertain. For some reason my canopy is resonating when closed. With the canopy open I really cannot hear the Koralia run over the gentle hum of two other powerheads and two XP3's below. In which case I would call it very quite for its flow. But when my hood is closed the pump makes a fairly loud hum. I'll call it an issue with my hood since when open the pump runs very quiet, and I'll try later to move the pump around and see if I can figure out why my canopy wants to amplify the hum.

The K4 is their biggest BTW, for smaller tanks they do make smaller pumps. These are intended for my 240G were I will have at least 2 of them for supplemental movement. I will soon be making a screen to cover the intake, and I'll post that info when I do.

[crazy loaches]

As promised I made a screen for it that prevents any fish from being able to fight through the current and get in through the front of unit. Its actually dual purpose, as it goes all the way back to the center of the housing it also protects the intake strainer from very small fish that might be able to get through its openings were the intake draw is the most (but the back half would still be susceptible), but I think the strainer is small enough except for the smallest of fish, like perhaps some tiny shrimp or something like that.

All I did was take some stainless steel screen and worked it by hand into the shape needed, making a couple creases and a few cuts in order to get it to shape. I dont know if it could potentially collapse as half of it has pressure sucking it inward, it seems rigid enough to support itself. At this point only time will tell since I am now using it. But if needed I thought a way to remedy this already - I could make a hoop at its widest point and when I fold the edges over I could fold it over the hoop and go around it with silicone and that for sure would stop it from collapsing, but I dont think its necessary at this point.

Here are some pictures:









So if your a bit crafty you can have a affordable high flow effecient powerhead that should be loach safe.

[Littlelady]

That looks really good, well done! It's very clever the way you have made the screen...I have seen these advertised and often wondered how good they were but disregarded the idea when I saw how big the gaps were on the front. (although like you said, there is quite a current to fight if any fish were to end up in there)

Please keep us updated!

[Keith Wolcott]

Yes, very well done.

[crazy loaches]

Thanks. I forgot to mention too that in case anyone was wondering the screen doesn’t seem to make a noticeable impact on flow. It will probably require a bit more maintenance since its trapping a little bit more stuff due to the finer mesh but no big deal. The mesh is a little more open that what it appears in the photos, I think the added flash makes the wires look bigger but they are very fine wire in it.

[Curtis]

How is this pump working for you now?

[Mark Janssen]

i had one but toke it bake to the store...

a 2500 koralia makes less water shift than my 1000liter powerhead in one of my tanks.

it certanly moves as much as it says. but it's a wide stream so after 30-50cm you don't feel the current anymore.

[crazy loaches]

How is this pump working for you now?

Working fine. I still havent got the big tank running yet (reason I got the K4's) but I've been running 1 in my 75g since I got it. I took the screen out since lately I just havent had time to clean it out frequent enough with all the plants... and it was just plugging up to much. I havent had any fish/propeller incidents.

I've also seen they make propeller like conversions for maxi-jet powerheads now... but the propeller looks even more exposed than the K4. Take a look here: www.premiumaquatics.com

ANd sorry about the pics not loading if anyone is wondering, I re did my webserver and not everything is put back yet. Hopefully in a couple days I should have time to get everything back.

[Curtis]

Thanks for replying I know this was a somewhat old post.

What kind of fish have you had with this pump/powerhead? I'm just curious about which loaches and so on ... since you haven't had an issue with it to date.

[crazy loaches]

I currently have clowns, yoyos and zebras. The clowns are the only ones that really hang out by it, and are often seen swimming in place in front of it. I havent seen any try to actually swim into it (but of course I am only watching my fish minutes out of a day) but whats worried me is that often the clowns will swim over it like searching for food stuck in the intake screen or even rest on it - I fear there fins might still be able to be pulled in through the slits. But no damaged fins as far as I can tell. I've even seen a small striata rest right on it. Since the intake is so large there isnt much suction per each slit, and the fish have no problems even when resting on it. A hillstream loach might though, with there wider profile.

Of course some loaches might be more inquisitive, and wonder whats inside it. But so far its been a good half a year and all seems well so far.

The only issue I've seen is I am less than pleased with the magnetic base's holding power with 1/2" glass. Hydor says they have not had/heard any issues with 1/2" glass and even sent me new magnets. But to get it to stay in place I really need to push it hard into the glass, basically using the suction cup power and not really the magnet. I might try to DIY up a stronger magnet though...

Oh, I guess there was still one more issue... the price! I dont understand why these are any more expensive than a regular powerhead. The only real difference functionally is the shape of the impeller. The motor is that of a very small powerhead, same style permanent magnet impeller on ceramic/steel shaft (depending on model) and instead of having a lift tube adapter and nozzle it has a large plastic 'cage' around it that cant cost more than $1 to make. That cant really be more costly. It must just be because there not common yet. Still cheaper than the Tunze though, basically the same flow numbers as a Tunze Turbelle Nano Stream 6045, but the tunze seems to run about $100 and I got the K4's for under $50.

[crazy loaches]

Well since I try to be as honest as I can, I'd like to report my first loach injury with this water pump. It is a lot my fault though.

Here is the story:
I normally have a small maxi-jet powerhead on my night timer that comes on near the waters surface at night since I run co2 injection. When not needed it helps degas co2 and promote o2 by agitating the water surface at night when the plants dont need co2 and do not give off o2 either. But I removed this ph recently. To make up for it I took the K4 which I normally have set nearer the bottom and put it a few inches under the water line. This proved to be a bad idea. I had been busy and hadnt fed my fish in a few days, and well, they were going nutz. The clowns will usually come right to the top for even just flakes. Well they were darting about trying to snatch food and one shot right into the K4! The whole fish was inside it and I heard it hit the propeller and it shot back out. Luckily it seems like it only got scratched and not cut deeply, but time will tell. I am not sure if I should try and put anyhting in the water for him, unfortunately my QT tank is packed with new fish for my 240g project. I did manage to get a pic of it just now:



My loaches normally feed somewhat confined to a small area on end (because of a large chunk of driftwood with java ferns that goes all the way to the top), which further increased the odds of an incident since the powerhead was on that end as well. I probably should have realized this, so I think this was mostly my fault. Or if I could have left the screen on this wouldnt have happened. But I just dont have the time lately to keep up with cleaning it with all my plants - it get clogged in just a few days.

[Rocco]

But I just dont have the time lately to keep up with cleaning it with all my plants - it get clogged in just a few days.

I share your pain regarding the plants its so nuts that I have to clean my foam pre-filters every week.

[shari2]

Keep the water clean and it looks like it might resolve on it's own, Tristan. If you're worried about it, or see any signs of a problem with it, you could use Melafix.

[bslindgren]

I have had Koralias for some time. The loaches do like to feed on the cage, but I have had no problem at all with any injuries in spite of this. I like them for giving good (quiet) water movement, but they probably wouldn't be the best if you want concentrated flow over some specific area, e.g., for hillstreams or similar.

[Rychek]

I've got a Koralia 2 and it came with a "nose cone" that cages in the large openings in the front. Nothing short of fry could fit through the holes now. Did yours not come with a nose cone or is there a reason you choose not to use it?