K Evolution Flowing Backwards?

Pufferpunk

Pufferpunk

New member
Is this possible? I noticed the water is flowing in the front & out the sides. The impeller only goes on one way.
 
I've read about the old koralias sometimes starting backwards, but this is the first I've heard of the evos doing it. Try to restart the pump. Otherwise, I'd get another...
 
Yes, especially if they are turned off and on quite a bit. There is a small plastic stop at the base of the propeller that keeps it spinning the right way. After enough start/stops the little stop wears off and it's a crap shoot of which way it will run. Doesn't matter what anyone says, AC (on/off) powerheads are NOT meant to be used on wavemakers or started and stopped often. One of the reasons I think their new "smartwave" is such a joke. This is a very common problem with the Koralia Evolutions. Quite a bit of talk on Reef Central about it.

One of the many reasons to go with a quality powerhead like Vortech or Tunze.
 
I only turn it off to clean it. That's not to often, maybe 4x since I've bought it about 1 1/2 years ago. The stop is still secure. 1st thing I checked was to see if the impeller was in backwards. That can't happen on these. Not everyone can afford a higher quality pump, especially with as many tanks as I keep. The cost differences aren't worth it to me.
 
The stop may look secure, but it is worn down. Either that or the impeller is not pushed all the way in. Those are the ONLY two things that could make that pump run backwards. Koralia was offering improved replacement bushings (which all of the new gray box evolutions are sent with) but the problem still exists. You get what you pay for.
 
They have excellent customer service. I'll contact them. I'm sure they'll send me a new one, since they're so cheap!
 
I had a pair of brand new 750 evos, they were MAYBE turned on and off 4-5 times before i started using them on my RKE in wavemaker, from day 1 of using the wavemaker it was a crapshoot if they would pump the right direction or pump backwards. I gave up and put them back on constant mode. I finally gave up on the pair and got a Vortech MP20, and my corals had never been happier, it literally did a better job than BOTH the koralias it replaced, at just about the same total turnover rate. I got a great deal on an MP40wES so I upgraded and love the extra flow. Ill likely never go back to cheap AC motor powerheads if i want reliable flow or wavemaker use.
 
Both of my evolutions had holes in the front grate indicating that the stops broke off and shot through the front. Infact, I noticed one time that the pump wasn't running and upon further investigation, loose broken pieces inside had it blocked. Once removed, the pumps worked again. I am convinced those where the stops.

Either way, mine were on a controller and were cycled on and off as the manufacturer says they are capable of doing. Within a year they were starting in reverse probably 50% of the time.

I threw them out and went to 2 MP40s. I realize that its expensive, but I think the only alternative is to continue replacing the korelias which in my opinion has the potential of being more expensive in the long term.
 
jcarlilesiu said:
Either way, mine were on a controller and were cycled on and off as the manufacturer says they are capable of doing. Within a year they were starting in reverse probably 50% of the time.

I threw them out and went to 2 MP40s. I realize that its expensive, but I think the only alternative is to continue replacing the korelias which in my opinion has the potential of being more expensive in the long term.
Click to expand...

did the same, had them on my apex, they worked fairly well, but do break down over time, stop, spin backwards...

I went the MP40w route as well
 
Email from Hydor Customer Service:
There are three possible causes of the reversal in the Koralia Evolution. You may have the old style of bushing that has slipped out of place.



This problem is remedied by the installation of the new style of bushing.

The another possibility is that the front cover is damaged. Make sure the black rubber bumper located on the inside of the front cover is undamaged and in place. Also make sure that the plastic around the bumper is not cracked.



The third possibility is that the magnetic shaft is cracked or swollen. A broken impeller magnet would also result in vibration and noise from the unit.



Let me know what you find.
Click to expand...

Gonna go look now.
 
The 4th possibility and most likely is that the pumps simply aren't intended for repeated on/off duty cycles and simply start up in reverse like they shouldn't. Mine were in perfect condition and still turned on in reverse 1:5 of the time once I had them on a wave-maker timer. AC motors just aren't made to operate the same as a quality DC brush-less motor. There's nothing wrong with Hydor Koralias, they are GREAT pumps for what they are and used as intended. Plug in, set, and forget.
 
FishBeard said:
The 4th possibility and most likely is that the pumps simply aren't intended for repeated on/off duty cycles and simply start up in reverse like they shouldn't. Mine were in perfect condition and still turned on in reverse 1:5 of the time once I had them on a wave-maker timer. AC motors just aren't made to operate the same as a quality DC brush-less motor. There's nothing wrong with Hydor Koralias, they are GREAT pumps for what they are and used as intended. Plug in, set, and forget.
Click to expand...

That is it. PERIOD. Hydor won't admit it but THERE IS NO AC DRIVE PUMP INTENDED FOR ON/OFF DUTY CYCLES.
 
The only thing I can assume is momentary power loss on the circuit the pump is plugged into. Just long enough the pump shuts off then fires back up in reverse. I highly doubt any fish/inverts are sabotaging your pumps...
 
Heh, how do we know what they do in the dark of night??? Sneaky lil devils, I say! :peep:
Especially that Mantis--he's always looking at me suspiciously, with those bug-eyes of his.
 
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