Plumping the BK 300 External

[pyke]

So I have this beautiful piece of artwork just sitting on the floor in my house called a Bubble King 300 Deluxe External that I want to install on my tank in the next few weeks and I am looking for some installation advice on this.

The guy I got it from had it being fed off his main return pump and feeding back into his sump. Does this cause any issues as the head feeing the skimmer is going to be significantly higher then the NPSH of the skimmer pump, hence causing more water flow then the skimmer is designed for.

So would it be better to plumb the inlet of the skimmer directly off the overflow (maybe 3ft of head) or off the side of the sump? or is feeding it with the return pump the best bet?

[Delphinus]

Couple ways of looking at this.

If you T off the sump return, put a valve inline to throttle the flow feeding the skimmer. That would work. Many years ago I ran a tank like that and got away with using one fewer pump.

If you can run off the overflow though then you are skimming the dirtiest water. Lots of advice out there regarding feeding skimmers raw overflow water, or at least partially or having the feed pump in the section that the overflow flows into. The downside is that unless you skimmer is huge in comparison to your sump return flow, you can't feed full-bore into the skimmer as it will overflow the skimmer (in typical cases anyhow). And if you skim only partially off the overflow, any DOC to be skimmed have to recycle through the sump and main display before the skimmer has a second chance at skimming any of it.

The last scenario is using a feed pump independent of the sump return. Then you can feed off the first section of the sump and direct the effluent back into this chamber. Water theoretically then has a chance to make several passes to recirculate through the skimmer and thus any water exiting this first chamber into the rest of the sump (and thus the main display) is theoretically as clean as it's going to get in the time it gets to spend in the sump.