# Koralia Circulation Pumps



## rjordan393 (Nov 23, 2012)

I am thinking of replacing two power heads with Koralia circulation pumps. They will take up less room then the power heads. There are two models that I am looking at; the 240 gph and the 425 gph. These models are more versatile. I have a 75 gallon tank. Which of these two models will serve me best? Anyone have any experience with these pumps? I just want enough flow to see some movement of my plants, but not too much that makes them look like they are in a storm. If I purchase these, they will be placed in the back corners of the tank and aimed just off center of the front glass. The resulting flows when they meet should give me a counter clockwise flow on the left side of the tank and a clockwise flow on the right side. I have my plants placed in a way whereas the main thrust of the flow will by pass the nearest plant as it heads for the front glass.
The important thing is the dealer does not take returns with used equipment. In case the 240 gph model does not satisfy me, then I am stuck with them. Hopefully, on my next visit to the store, the dealer might have a demonstration model already set up.


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## ObiQuiet (Oct 9, 2009)

Here's a video of one of my 425s in action:
https://www.dropbox.com/s/k6whbtbgr9ltesr/20150301_220157.mp4?dl=0

The Koralia 425 is on the right end of a 110gal, 5ft tank, pointing right-to-left (not back-to-front they way you have in mind). The flow hits the front glass about mid-way. You can see the motion of the vals there in front. There is much less motion all the way on the left side.

The pump timer turned off right at the end of the video - that's why you see the vals straightening up again.

I hope that helps you choose; let me know if you have a question!


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## rjordan393 (Nov 23, 2012)

Thanks,
It looks like two of the 240 gph will work well for me. I noticed that one reviewer had a problem with a much higher flow Koralia. When he turned it off and then back on, the impeller will go in reverse. Have you had this problem with your 425 gph?


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## ObiQuiet (Oct 9, 2009)

I haven't noticed any backward motion, but maybe they do from time to time. They're on about a 50% duty cycle, 5mins each time -- so that's a lot of on and off.


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## rjordan393 (Nov 23, 2012)

Thanks again,
I forgot I had a 500 gph circulator pump and I place that in service to see how it affects my plants. It was way too much; so I will settle for two of the 240 gph Koralia's.


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## rjordan393 (Nov 23, 2012)

Update:
What a disaster. The Koralia 240 gph circulation pump does not even come close to its rated output. I placed my hand about 6 inches away from the flow and can feel how weak it was. It's so weak, I could not see my plants moving.
It was supposed to replace an "Accella" power head rated at 266 gph. The "Accella" does the job but the Koralia is a much smaller pump, which is the reason I purchased two of them for my 75 gallon tank. Unfortunely for me, the store would only credit me for one pump because the package for the second pump was not opened. So it cost me $36.00 for junk and a pump I cannot use. Investment $72.00, results zero. I sent an email to "Hydor" stating my displeasure over the performance of this pump model. I read a few pages of reviews on the Koralia pumps and it appears there is a quality control problem with these pumps. Some of these pumps are getting out on the market and the pumps do not live up to the stated output.


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## ObiQuiet (Oct 9, 2009)

I'm sorry to hear that...


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## rjordan393 (Nov 23, 2012)

I also saw a company video of the Koralia 240 gph pump and the pump was just an inch below the surface. Now I think I know how they rated this pump. While the pump is about an inch below the surface, there is not much pressure up against it. But if placed 6 or more inches below the surface; then you have pressure up against the propeller from some of the the weight of the water. In other words, head pressure has to be taken into account when a circulator pump does not have the torque to over come it. Just my theory but I think I am close.


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## kwroberto (Jun 25, 2013)

I have the Hydors on my planted tank (75gallon) and I'm using 2 750s.....I have the mp10 by Ecotech and they are wayyyy better mainly because of the control its on my other 75 planted tank...I know they are suppose to be for reef tanks but I love them on my planted tank!


Sent from my iPhone using Tapatalk


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## fastlight8101 (Mar 12, 2015)

What if he hydro 425gph is pumping the rated gph? But because the pattern of water coming out of the pump is wide instead of narrow, it doesn't seem as if it's as powerful as you think it should be? I put a hydro nano in my 72 gallon bow front, and I feel it's sufficient flow. But that is a matter of opinion. Probably only was to get exactly what you want is to buy oversized pump and control the flow with a controller?


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## rjordan393 (Nov 23, 2012)

The 425 gph koralia I believe would give me enough flow and current to make my plants move. This would tell me that the nutrient content of the water will get to the plants without fear of dead spots. but these pumps are overpriced. I looked at the video a member uploaded of his 425 gph in his 115 gallon tank and it was moving a val which was about in the center of the tank. So I reasoned that two 240 gph Koralia circulator pumps placed on each end would satisfy me in my 75 gallon tank. I was wrong. I tried to reason with the distributiors of Koralia but got nowhere. Now think about this: Their company video shows this pump about an inch below the surface and that is how they judged it's gph. But I say if you lower it 6 or more inches below the surface, then the propeller of the pump bears some of the weight of the water. Then it does not give the rated flow which forces the purchaser to upgrade at an additional expense for a stronger over priced pump or use another manufacturers pump.
Right now, I am using two "Seio" circulation pumps that are just 26 gph more then the koralia 240 gph and they are performing as expected and they are 6 inches or more below the surface. The koralia pumps are designed for wave making and they do not give the rated flow below the surface.


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