How to choose appropriate skimmer size?

[d2mini]

Jeremy, you've mentioned that when choosing a skimmer size you should go by display volume, not total system volume. But what about frag tanks or refugiums that are part of the same system? Should we include those?

 

[Jeremy B.]

I go by display volume assuming you have a normal size sump (20 - 50g) that is not stocked. If you have a 40g sump that also acts as a frag tank, then I include that in the display volume. Whether you have a 20g of just sump water, or another 50g of sump water, that really doesn't play it into your stocking bioload much, and it really doesn't make a big difference in terms of going from a 6" body skimmer to an 8" body skimmer. If you have a 100g sump on say a 90g display, then that makes a bit more of a difference even if it's not stocked with anything.

I hope this makes sense?

 

[d2mini]

Yeah, i think so. haha

I have those rubbermaid stock tanks as sumps. A 150g with my live rock and a skimmer box with filter sock. I have a second 75 gallon tub that is part refugium and part frag tank.

My display is 84x24x24.

Right now i'm running a used vertex alpha 250 but we've already determined it's too big for my system. It's been impossible to dial in any kind of consistency. So just want to make sure I size my next skimmer correctly.

 

[Jeremy B.]

So really your stocking volume is about 285g (tank + frag tank), and then you have a pretty decent size sump with it. With the neck size of the Alpha line they almost act a little more like a size up in skimmers, for example the Alpha 250 which is 10" is more comparable to most other manufacturers 12" skimmer, etc. Not all Royal-Exclusiv skimmers are like this though, for example the Mini's and the Double Cones use smaller necks in ratio to their body size. The Super Marin's still use really large necks, but they also process more water than what the ALpha's do, combined with the coned bubble plate.

If you are looking for another RE skimmer than I'd suggest looking at the Double Cone 200 or 250, or the Super Marin 200 or 250.