# Light dimmer to control powerhead?



## stripe157 (Jan 4, 2010)

About a month ago I ordered a SEIO pump from Foster and Smith. I liked that one because it was adjustable. I showed up, and after getting it installed, I decided within a few seconds that it was unacceptably loud. I sent it back to F&S for an exchange for a Koralia 1. Those are on back order, so I opted to exchange for a Koralia 2 instead. It's a nice pump. It's quiet, looks to be great quality... however; that thing moves some water! My school of 10 black neon tetras seem to be able to do nothing swim for their lives to keep from being sucked into the back of that thing. 
I"ve already spent too much on shipping to send it back again.
Is it possible to use a light switch dimmer (thyristor) to vary the 'power' to the Koalia pump? Any other ideas?

Also, Koralia makes different pumps for always-on, and pumps for wavemaker applications. The normal pumps are not meant to be turned on and off repeatedly... Can I put this on a timer and turn it on and off ONCE a day?


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## stripe157 (Jan 4, 2010)

The dimmer thing isn't going to work. I just tried it. The impeller twitches some, but no water movement.


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## DarkCobra (Jun 22, 2004)

Yep.

Normal dimmers are made for resistive loads (like light bulbs), and usually fail to operate properly when connected to inductive loads (like motors).

There are some specialty "dimmers" made for inductive loads, like ceiling fan speed controls. But what I typically see in filters are synchronous AC motors; their speed is determined not by the power going through it, but by the frequency of the AC line. I know of no way to successfully modify their speed, restrict the power and they operate erratically or stop.

Best to solve this one by restricting or spreading the water flow.


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## OverStocked (May 26, 2007)

Easy way to fix this... 

either use a little mesh to clog up the intake, or some silicone allowed to cure fully. Just cover up a few slats at a time and see what you get. This will inevitably cause the early demise of your pump, though.


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## kyle3 (May 26, 2005)

hmm that's a tricky problem. 

could you use one of those "breeder" nets that have a plastic frame to keep your fish from getting sucked in? I'm afraid that would be terribly unattractive but what if you custom built one just slightly bigger than the korelia and used a black mesh fabric, might look a bit more unobtrusive. you much of a seamstress? 

hope you find a good solution!

good luck-K


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## Wasserpest (Jun 12, 2003)

You could put the Koralia up in the Swap section to exchange for a smaller one (1 or even better Nano, depending on your tank size). I am sure there is someone out there who would like to trade up.

And yes, shouldn't be an issue turning the pump on and off once a day. Better solution would be to use a properly sized one and let it run all the time.


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## stripe157 (Jan 4, 2010)

I was in the process of sewing up some filter pad to stick on the back of it, got halfway through and realized that this is not one of my talents.
I may be able to sell it a friend with a more 'appropriately' sized tank.
Oh by the way, Foster and Smith don't even have the koralia 1,2 listed anymore...
are they coming out with a new model I wonder?


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## OverStocked (May 26, 2007)

stripe157 said:


> I was in the process of sewing up some filter pad to stick on the back of it, got halfway through and realized that this is not one of my talents.
> I may be able to sell it a friend with a more 'appropriately' sized tank.
> Oh by the way, Foster and Smith don't even have the koralia 1,2 listed anymore...
> are they coming out with a new model I wonder?


They are. It is advertised in TFH magazine as smaller.


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