Refugium Thoughts

[umbis]

I'm setting up a new tank this week. A 75 gallon display with a 20 gallon high sump. I've got the sump built:

1st chamber: skimmer
3 baffles
2nd chamber: refugium
baffle
3rd chamber: return

The fuge is about 12 x 12 & 8" deep. I want to have the best nutrient export possible from the fuge. Should I go with a DSB, SSB, or BB? Also, is LR or LR rubble even useful? I'll have around 50 - 60 lbs in the display. I'll for sure be growing lots of cheato.

Thanks.

 

[AdInfinitum]

I'll give you the short answer (not easy for me) but...IMO based on decades running systems from the "dark ages" until now...

You would be best served not even thinking about a refugium as a means of nutrient export at all.  Yes it will do a bit of that if your chaeto grows well enough that you harvest large amounts on a regular basis and nutrients will be temporarily bound into other organisms that will grow in your fuge.  But unless you keep your bio load in your DT extremely light a refugium alone will never keep nutrients anywhere near the levels demanded in a modern reef tank.

The idea of a refugium as the means for nutrient export developed back when we had no other options.  It can be done...but it usually requires systems where the fuge is much larger than the display.

In a modern reef the invaluable role that a well developed fuge can offer a system is as a source of bio-diversity and constantly available foods for our DT inhabitants.  Phyto, Rotifers, Pods, Mysis,and bits of edible Macros slowly and constantly washing into the tank so that fish and corals can graze and feed constantly and naturally not just at "feeding time".

For most peoples' systems nutrient export is best handled easily and painlessly with a good skimmer, GFO and bio pellets.

Ok not so short...

A good environment for pods and mysis has some substrate and some rock or rubble but not so much that detritus will accumulate in the lower flow areas.

 

[Pistol]

+1
Also DSBs are not worth the trouble they can cause, they tend to cake up and become nutrient sinks and H2S bombs, and lighted sumps cause algae (good and bad) to grow on your skimmer and pumps and other equipment. I prefer a blacked out tank (lit opposite the display period) to grow macro algae separate from my sump.