Hi,
I have a Mini Bubble King 180 Gen 2 and was wondering if I would be able to swap the current AC pump with the DC RD3 Skimmer pump used in many of the new BK skimmers. It seems that many of the DC skimmers are rated for tanks larger than mine. I'm trying to get the aquarium as quiet as possible and my BK mini makes a humming noise that is the loudest thing in my tank.
I have a 135G Fish Only tank with a 30G sump.
Irwin
The Mini 180 will not support an RD3 pump. The only Mini skimmer that does is the Mini 200. That said, the existing pump should be virtually silent. If it's not nearly silent, you have one of 3 things going on. One is the bearing may causing friction with the impeller shaft. The second would be that the skimmer is assembled in such a way that a part of the pump body or the outlet is kind of tweaked enough that the pump is resonating through the skimmer body and lastly it could also be noise generated from the air path. This assuming that the skimmer body isn't touching something in your sump.
First thing I would suggest taking the pump completely apart, removing the impeller and removing the bearing that sits in the magnet cavity. If when you pull the impeller out of the motorblock, the bearing is stuck to the bottom of the shaft, that is an issue and it will need to be careful pulled off the shaft. The bearing should never stick the shaft and should always be seated in the bottom of the motor block. See link to instructions below.
Once you have everything apart, soak all the parts in vinegar for several hours. Then scrub everything well with a soft brush and rinse well. The pump should look like new inside and out. Make sure the little hole in the bearing that the impeller shaft sits into is nice and clean. A tooth pick can come in hand for cleaning that hole. Then reinstall the bearing correctly. It's critical that the o-ring on the bearing be properly seating into the bearing cavity when you reinstall the bearing. If it's not seated properly, the bearing will create friction on the end of the impeller shaft. Also, make sure the end of the impeller shaft is clean and smooth. A scotch Brite pad can come in hand for cleaning the end of the impeller shaft. Also inspect the nipple where the airline connects to the pumps nozzle and make sure there is no salt creep in there. Again, a toothpick can come in handy cleaning any salt creep out of the airline connection at the pump. Once you have it all back together, run the pump in a bucket with vinegar for a few hours and then run it in fresh water for a little while before putting the skimmer back together. When you reassembled the skimmer loose fit everything first then tighten one section at a time working from the bottom of the skimmer up.
The other think I would do is dissasemble the silencer (AKA resonator), remove the foam filter and rinse and clean it thoroughly followed by allowing it to air dry completely. Also clean the resonator body inside and out making sure to inspect and clean the red rigid air path tubes inside the resonator body.
The bearing inside the motorblock is discussed on page 7 of the manual and the resonator is discussed on page 9 of the manual below:
http://royalexclusiv.net/images/content/mbk/eng/mbk_operating_maintenance_eng.pdf
