I would like to pass on something that I have discovered about the Hydor Koralia powerheads. First off let me lead off by saying that this is not intended to be an alarmist or the sky is falling type post. It is based on my observations and is provided for informational purposes to others in the hobby.

Background. I set up an extra 10 gallon tank about 18 months ago to serve as a frag and holding tank while I set up my 40 breeder. My equipment was a stealth heater, a AC50, a 80 watt Current CF light and a Hydor Koralia Nano. Initially everything did very well in the tank and growth was great. The tank allowed me to help some other reefers start up tanks with free frags and enabled me to continue to acquire new pieces in anticipation of my 40Br completion (my NC12DX was out of room). The Koralia performed admirably and I was happy with the flow and performance.

About 10 weeks ago I noticed that my corals started looking poorly and did not seem to be thriving. Growth rates became almost non-existent and coloration and polyp extension was poor. I tested for everything imaginable with no luck. I change the bulbs in my fixture with no luck. The only thing that seemed to help was 30% water changes every 2-3 days.

I finally got my 40 set up and transfered all the livesotck over. Within a week colors were coming back up and polyp extension was outstanding. I credited it to the new T-5's and went about my business until today. This evening I started breaking down the tank and cleaning the equipment in it for storage. As I was cleaning the suction cups for the hydor the magnet for the wet-side fell out. Lo and behold the rare earth magnet was severely corroded to the point bubbling was evident. Checking my dry side magnet I discovered that it is not sealed in any sort of epoxy or plastic either. They simply pop into the the suction cup piece. One side has the plastic cover and the other side shows the bare magnet that fits inside of the suction cup. This is obviously not a water tight seal. Please see attached pic: the dry side magnet is on the left and the wet side is on the right.


I will be the first to admit that any evidence connecting this to my livestocks poor performance to be purely anecdotal at best. I am merely passing this information on to others who may use this product so they are informed and can take any corrective action they deem necessary. I intend to continue to use mine once I have taken steps to epoxy the bare side of the magnet to ensure this does not happen again.

-Prof

Edited per Bonsais excellent suggestion. This appears to be a K-Nano issue

-Prof

Thanks! I have that exact same powerhead in my 15g. And as a testament to your hypothesis I have noticed poor coral growth and lack of coloration. Even with all my hard work... I chalked this up to my inexperience in nano reefing. Please post pics of how you seal the magnet to the suction cup, or advice on a comparable powerhead.

you suck.....


i just bought one.....where were you a week ago?

Interesting. Thank God for Vortech.

I know, My wife bought my a MP20 for my B-day for the new tank, but I have not installed it yet.

Please remember guys, I am not trying to throw Hydor under the bus, I am simply posting my experience.

If I come up with a way to seal the magnet, I will post it. Epoxy is one possible method. Silicone may be another. Whatever I do will have to be a thin coat in order for the magnet to still fit into the suction cup properly.

-Prof

+1

but in all seriousness it won't really do anything to your aquarium.

Explain please? Looking forward to your thoughts on the matter.

-Prof

look forward to a post on your fix. I like my #1 and will happily do the repair. Thanks

wouldn't a rusting magnet leach into the water? i'm not a chemist but it seems like bad news for a small bio-filter environment

i've been toying with the idea of getting a mp10...maybe i should pull the trigger soon.

what are others thinking?

second definition of Granular Ferric Oxide which we use for phosphate removal in our aquariums
http://www.thefreedictionary.com/ferric+oxide
simply put we use rust and is safe in aquariums as long as it is controlled. if i'm wrong i'm sure someone will let me know but that is why i stated it shouldn't matter too much.

I am sure it would wreak havoc, there was a thread on RC about a guy who's tank was in the crapper and realized that his mag float algae glass cleaner had a crack in it.
I will be checking my Koralias periodically. Thanks for the info Prof!

gfo and regular rust are different. I had the same issue with rust from a screw in my frag tubs. The Rust WILL cause problems in your tank. Good to know, guess i need to replace the koralia nano in my daughters tank.

Prof, when did you purchase your koralia nano? I'm wondering if they have corrected this in more recently manufactured pumps... I bought 2 Koralia 1's and I seem to recall that the wet-side magnets were sealed with something other than the suction cup (actually I recall that the whole magnet was epoxy coated). I'll take it apart tomorrow when I clean and take some pics to be sure.

can u just seal off the magnet inside the tank with epoxy or silicone?

^^+1 i was thinkin about getting a k1 from someone on here, do you think i shouldn't? what should i get then? thats under 40 dollars msrp im gunna try to get it off someone on here.

While iron may be a component in rare earth magnets, there are other items in their composition other than iron that could potentially leach heavy metals in your tank. Something to research.



No problem. I think the knowledge this is a potential problem is key. They are great pumps and I would hate to be the cause for anyone thowing theirs out.



^+1 on the rust. Inspect your pump in your daughters tank before you replace. It could be fine.



I purchased mine ~18 months ago. I sincerely hope they have improved the design. Let us know what you find out when you inspect yours.



I am sure you can. I intend to try with mine. I will post my methods and results once I figure out how I am going to do it.



You should decide whether you should or shouldn't. If you are buying a used one now you know something to inspect for.The pumps have a steller rep for a reason; they are great pumps for the money. One small glitch should not be a reason not to buy, particularly if they have recently fixed the issue or it is easily solved by you. I intend to try and will post results

-Prof

aright i'll go with a k1 i think its about 5 months old if i remember thats what the seller said

I have 2 of them, now they are K-4's, but the magnets in them are actually enclosed in hard plastic pucks....

is all I can say! Thanks for this info!! I wonder of the demise of my 10g custom AIO is attributed to the K-Nano pump I have in my tank. You'd think a company like Hydor would seal up the damn things at least in the wet side!! This kinda upsets me!!

the other thing i was thinking about, if the magnets are coated in some other type of metal. such as zinc, nickel, etc. They will def cause problems.

As long as you are being an informed consumer. Caveat Emptor!


Just interested - have you popped them out of the suction cup and inspected the other side? The front of mine has a plastic cover but the other side is bare magnet. LMK what you find please.



It is possible this was the cause of your issue. It was the only common denominator I could link to my issues. I hope Hydor has corrected this since I bought mine.


That was one of the elements that came to mind for me as well. I will take it for action to research the components in rare earth magnets.

-Prof

My K2 magnet is coated. I use a vortech now but never had a problem in the tank that could be traced to a Koralia. Must have went cheap on the nanos

Very possible Stevie. Looking forward to installing my Vortech

-Prof

Very
Very
Interesting...

We have found a new scapegoat!

Really though, I hope the new ones are sealed lol...I have several...

about 1000x better than the koralia. I am waiting on parts for my vortech (bad from the factory) so I had to go back to the koralia while waiting the few day. You really notice the difference then.

WOAH

That's a crazy realization. I have a Koralia Nano in my BioCube 8 ... I've never been happy with the coral in that tank, everything just kind of looks ... eh. Not great. Corals in my BioCube 29 are awesome, and that tank is running a Koralia 2.

When I get to the office tomorrow, the first thing I'm going to do is check the Koralia Magnets. In my case, both magnets are "wet" as I have the Koralia Nano positioned opposite of the output pump ... on Chamber One.

Damn - this would be a great fix to my problems.

got mine in the mail today



yeah, i just got my koralia 2 today, and when i read this checked it out. the whole wet and dry side of the magnet where covered, with no room for water leakage. they must have changed the design which is good for people still purchasing! oh, and for people that just got theirs in the mail!

Hope you found your smoking gun!



Glad to hear it. Sounds like they made a change. Quick question. Did you actually pop the magnet out of the suction cup and inspect the back of it?


I wonder if this is an issue only with the Nano?

-Prof

i wonder how many NR'ers went and checked their koralias after reading this

Hopefully a lot did. I posted my experience so other reefer's would be informed and could check their gear and take whatever corrective they deem necessary.

-Prof

^^^ Amen! ^^^

Holllllllllllllllllllly ####.

Okay, how do you pop these puppies outta there?
I'm trying to get my K1 magnet out of the wet side and I can't get it out.
Is there a trick to it?

Hmm. Not good. Guess you know what I'll be doing this evening.

Not really, the rubber covers just flexes off and the magnet pops out.

Thanks Prof, I'll check mine tonight.

This only applies to older model nano's, correct?

I have a K1 that is sealed. Better check my nano, though. Thanks for the info.

I just did a study on this in ocean systems for my university geology class. Rusting iron and Ferric Oxide and other emissions from rusting ships are actually beneficial to the ocean. We even experimented with similar concentrations as the iron:tank ratio that you're suggesting. Interestingly, the tanks we used were able to convert concentrations up to 1:15 before any side effects were noticed or measured. No damsels were hurt in the making of this post haha

Very thorough report though, i really appreciate these kinds of discussions! Anyone else?

The Koralia Nano might be in a soft plastic cover, but the Koralia 1 magnet is not.
It's seated in a hard plastic dealie and I can't get it out to check it.
I'd really like to though, cause I've had lots of tank issues for a while, and I'd very much like to know if this has anything to do with it.

The k2's i have are sealed, the magnets are inside the plastic pieces as you said but they have a piece of rubber covering the other side. I guess I just have the new ones.

I just check my Nano and had the same problem. I just removed the magnet and am now using just the suction cup. My K1 has the hard plastic cover you speak of and i also couldnt get mine out. Hopefully it has the same cover on the back...

This is Bad News Bears.

I just removed my nano and it looks like it has copper on it

that's it mines coming out. MP20 going in!

Well my dad's nano is out of bussiness. He had one in his 75 to just get flow behind the rocks and it's rusted. I just pulled it out.

Guess i know what i will be checking later....that sucks....any ideas to seal it up?? Maybe just some silicone??

Huh... guess I need to check mine.

Has anybody contacted Hydor about this?

Edited title per Bonsai's suggestion -this appears to be a K-Nano issue.

-Prof



Not yet Lani. I plan to email them my concerns this evening now that I have confirmation that my issue was not an isolated incident.

-Prof

+1.

I'm not one to give +1's

But........

+1