# Koralia I'm not happy !!



## harryH (24 Mar 2014)

I have the older style 900 ( not magnet sucker)  which ran quiet for a couple of months then started 'humming / buzzing'. I tried the  trick of making a washer by cutting a slice of airline and placing it over the shaft, also lubrication. This was fine for 2/3 days then problem would start all over again.

Having read the newer pumps were better, I bought a new one for £25 from a well known on line supplier which has the magnet, though in every respect the pump itself looks EXACTLY the same physically.
This new pump buzzes in the same way, most annoying, like having an airpump droning away.

Please can anyone tell me if the latest Koralia 900 is exactly the same physically as the old one or have I been sold an old model with a magnet fitting? Thanks for your help guys.

Harry.

Edit I had to cut off the moulded plug to lengthen the lead for my purpose so suppose the guarantee is shot.


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## kirk (24 Mar 2014)

I haven't noticed mine been too noisey but I've not done my ears anygood playing loud music and working without ear protection in the past.are you sure you don't just have super hearing. I did get a rattle once after cleaning it,  quick dab of vasaline hasn't been too noisey since. I have the magnetic type too purchased for the right money from a member here.


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## BigTom (24 Mar 2014)

I haven't used mine in a long time and to be honest can't remember if it was magnetic or not (I think it was, bought it about 4 years ago which I think is when they updated them?) but it also developed a rattle. It seemed to be due mainly to the impeller shroud - when I removed that it stopped. I also managed to snap the ball joint off the shaft the first time I tried to assemble it. Wasn't terribly impressed to be honest.


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## harryH (24 Mar 2014)

kirk said:


> super hearing.



Hi Kirk,
Super hearing at my age? you must be avin a larf mate. To be honest I can put up with it but it's the wife complaining and she has really bad ears if I am wanting something

Actually I have switched it on and off a few times and its a bit better but I really don't like to have any noise at all. I have a cheap Chinese pump cost £9 and it's totally silent, trouble with it is it doesn't give the spread and performance of the Koralia which in operation is actually a super pump.

Harry


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## kirk (24 Mar 2014)

I agree with the flimsy shroud too tom, I was worried about my sausage fingers breaking it as the bits arnt cheap either. Harry I may of just got used to it and I also run an air pump now.   Do you remember the old brass science lab piston air pumps mechanical? The sound was much more tolerable.


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## harryH (24 Mar 2014)

BigTom said:


> I haven't used mine in a long time and to be honest can't remember if it was magnetic or not (I think it was, bought it about 4 years ago which I think is when they updated them?) but it also developed a rattle. It seemed to be due mainly to the impeller shroud - when I removed that it stopped. I also managed to snap the ball joint off the shaft the first time I tried to assemble it. Wasn't terribly impressed to be honest.



Cheers Tom,

I was so impressed with my previous Koralia at first as it was totally silent. 
I was wondering if the Tunze Nanostream is any better?

Harry


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## BigTom (24 Mar 2014)

Try running it without the plastic shroud/grille on the front and see if that makes a difference. I don't recall mincing anything when I had it running like that, but it might have changed the flow pattern a bit.


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## harryH (24 Mar 2014)

BigTom said:


> Try running it without the plastic shroud/grille on the front and see if that makes a difference. I don't recall mincing anything when I had it running like that, but it might have changed the flow pattern a bit.



Worth a shot Tom, I'll give it a go. I'll let it run 24 hrs first and see if it dose get any quieter as some say they do. I think the design of the impeller is responsible for the flow pattern so should be okay. It appears it's the impeller vibrating and if it is vibrating where it locates the plastic shroud then it would make sense that it's quieter with that bit removed. Just annoyed at having to compromise on a brand new item.

Harry.


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## kirk (24 Mar 2014)

I've been putting off cleaning ours but I've just stripped it and re lubed it. Is this the one you have?


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## Wallace (24 Mar 2014)

kirk said:


> I've been putting off cleaning ours but I've just stripped it and re lubed it. Is this the one you have?



Same as mine is that, except mine has a black impeller. Mine was whisper quiet for about a year or so, then developed a loud rattle / vibration. Vaseline, job done. Quiet again. 

Today though I think I must of put too much on 'cos the blahblahblahblahblahblahblah thing wouldn't run. Quick clean up and re lube and it's whisper quiet again. In about a day or 2 though it'll start to get louder. 

Hey ho, you learn to live with it. 


Sent from my iPhone using Tapatalk


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## kirk (24 Mar 2014)

Ours will not run strait away I always have to flick the casing and off it goes, I've never been bothered by that.


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## harryH (24 Mar 2014)

Hi Kirk, sorry to be late replying ( family visited).

Yes that is exactly the one except again mine has the black impeller. Wonder why some are white and some black? there was some word that they had improved the impeller design, could the white one be the mod.? Anyway it's still doing my head in so I off to have a go at it..watch this space.


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## harryH (24 Mar 2014)

Okay all, I just stripped it down, placed a 2 mm washer (airline) over the white bit on the base of the impellor. Next I placed another 2 mm airline washer over the plastic shaft inside the cover/grill so that when the impellor fits over it , it is running on this washer like a bearing. Then I gave a good smear of vaseline to every moving part (and maybe some that don't move .)  Now it's back together and silent.

The thing is I shouldn't have to do this with a brand new item. I have little confidence this will work for long as I was doing this with my old pump and was lucky to get more than a couple of days peace.

Anyway I plan see how things go and the only other thing I have up my sleeve ( apart from a gallon of aquarium water) is that if all this doesn't work I'll try removing the grill altogether.

I plan to keep updating this thread as I go along as I'm sure I'm not the only one with this type of problem and it may prove useful to someone.

Meantime I would be more than happy to receive any advice along the way. Cheers, 

Harry.


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## Andy D (24 Mar 2014)

I have a 900. Mine vibrated and I used to think it was the impeller section but it was actually where the cable was in contact with the tank that was causing the noise. 

Once I had this in the right position it was fine.


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## kirk (24 Mar 2014)

Good point Andy also if it collects trimming.  I wouldn't run mine without the guard as I don't want to see crs soup at lights on.


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## harryH (24 Mar 2014)

kirk said:


> Good point Andy also if it collects trimming. I wouldn't run mine without the guard as I don't want to see crs soup at lights on.



Good point Kirk. That is a huge consideration. I know the impeller tends to blow things away but there's always a risk.  Even with the cage on ( if the pump is off at night) there is always a possibility baby shrimp might crawl in only to be blitzed once the pump starts again? Mine tends to run 24/7.

Harry


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## kirk (24 Mar 2014)

24/7 here too. Keep us  updated with you mod it may help others as they are so popular.


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## harryH (24 Mar 2014)

kirk said:


> 24/7 here too. Keep us  updated with you mod it may help others as they are so popular.



Will do Kirk. Cheers

Harry.


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## harryH (28 Mar 2014)

Hi, here is an update.
I have had the pump running Monday to Friday now since the adjustments made see above posts.

With apologies for the elementary content as I am aiming this at those not to familiar with this equipment.

The pump has remained silent up to about an hour ago when I moved it ( forgetting about the exterior magnet sucker) in order to do some work (cleaning)on the tank.
It wasn't until I'd finished my work that I heard something drop and immediately the pump became audible with the familiar hum!. I'm a bit slow these days so it took me a few seconds to realise it was the exterior magnet sucker that had dropped down the back on to the floor.
I retrieved the sucker and went to replace it and immediately I held it in the vicinity of it's corresponding internal part the pump fell silent. Once connected the pump ran on silently.

The point of telling you all this is that until now I was under the impression the magnet suckers were there solely to hold the pump firmly in place. It is now obvious to me they do much more. In fact the pump fell silent BEFORE I had made contact with the glass with the retrieved sucker. I was probably half an inch away.

I seems then that the magnet sucker actually has  a bearing on the magnetic impeller in such a way it is designed to hold that part from vibrating whilst also holding the pump firmly in place on the glass.

As I said, apologies to those well familiar with this...I am now one of you.
As for the pump..so far so good!!

Harry


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## kirk (28 Mar 2014)

Nice one arry! they are a seriously strong magnet I suppose it makes sense the speed they are spinning.  Good informative post mate. Cheers kirk.


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## Cherry (7 Apr 2014)

hmm _ I am late to this thread ,however a related question - I had one with a magnetic thingy - was quiet BUT has stopped doing anything! ie it whirls away like a good un , bu when I tested it realised it wasnt moving the water at all. Anyone any bright ideas ( I bought a new cheaper one that is doing a great job , but loathe to throw this one away -scottish blood) I stripped it down - well took it apart - doesnt appear to have made any difference!


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## harryH (7 Apr 2014)

Hi Cherry,


If it's whirring away but not moving the water I can think of two things I would be checking. Firstly is the impeller stuck (jammed)? secondly I have known impellers to come apart from the magnet in such a way that the magnetic part of the impeller spins but the blades stay still, in which case the only fix is a new impeller.

T

Harry.


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