Koralia Evo with lamp dimmer

I have 4x Evo 750 in my 40b. I do have very nice surface agitation and water movement, but still get a lot of dead spots where I see detritus gets accumulated. After reading some threads about wave makers and that is not a good option for my powerheads. So what I'm thinking about is buy 2 lamp dimmers, 1 for each side (2 powerheads) and try to slow them down about may be 50% when I go to work, once back from work switch to another side and when go to sleep - both sides back to 100%. Will it work?

Credenza 300 Watt Lamp Dimmer - Black-TT-300NLH-BL at The Home Depot

 

I dont know but that dosent sound un-fesable as long as you match the dimmers amps to the PH amps when you dial down the power to it.

my electric skills are terriable so this is just a basic thought

 

Typical dimmer packs will supply power to motors and make them run, but the dimmers aren't designed for it. Some dimmers can be damaged by connecting inductive loads to them. And when the triac fails half-wave it takes the motor out too. A good idea to protect motor failures is to use a fuse sized for the motor load in series with the motor. This fuse will propably burn before motor is damaged if it is sized correctly.

Light dimmers designed for inductive loads work quite well with universal" or AC/DC type motors. Typically, these have brushes and are used in electric drills, vacuum cleaners, electric lawn edgers etc. With this kind of motors a proper dimmer works well.

The motors used in powerheads, pumps and fans are quite likely induction motor which are not very well controllable. Those motors in powerheads are square-law devices, most of the speed control will be at the end of the dial but that would be true with any control. The "dimmers" designed for ceiling fan speed control work quite well and also some normal light dimmers designed for inductive loads.

If the dimmer approach not satisfactory, then remeber that electric motors are usually and is best controlled by a small variac, tapped ransformer, rheostat, series light bulbs, etc. which do not mess up the sinusoidal waveform. Even this method does not help in controlling a syncronous motor, which always tries to rotate at the same speed suncronous to mains power.

Hope this helps, also 100 watts is 1 Amp the fuse should hold slightly over the powerhead rating so a 1/4 amp fuse would work for let's say an 18 watt powerhead. It is not recommended but very well possible. But if not fused correctly you can just burn out the motor. Not sure of the wattage of that specific Koralia Evo.

 

Great info, thanks a lot.