Why is a refugium necessary with corals?

[Louis Z]

I have a FOWLR . I had issues with black cyano , lyngbya, GHA . Slime away and chemiclean killed off the cyano and lyngbya bacteria . Tried fluconazole , nothing . the black cyano was killing GHA but also affecting my fish so I had to chemiclean . I then did lights out for GHA for 3 to 4 weeks on both upper DT and lower Refugium . GHA didn’t survive with only ambient light . Fish ok . , I started to ramp up lights and no GHA . Waited to add chaeto . Nitrates shot way up , over 100 . Did water change and added chaeto , Nitrates down to less than 20 . So Refugium necessary for me . I have healthy supply of amphipods , copepods . On my way to having skimmerless and no filtersocks. Added little neck clams to sump and I just added live red sponge to Refugium and ghost shrimp . I will add more clams and sponges as time passes . I really hope to have a whole ecosystem with different inverts and macroalgaes . Less Tech .

 

[BoaConservationist]

As many others have already pointed out, a refugium isn't absolutely necessary. I'll add a different perspective...I love the look of macro algae in the main display, even though it's not super popular. It's a cheap and easy way to add color and movement while helping stabilize N and P, especially in a smaller tank.

People forget they can just put it in the tank, make a corner with 3" sand bed and grab some pom pom and youre set, if you need to drop phosphates harder get some octhodes / hypnea, a blue variant. :) BRS has done a good job of scaring people of anyones algae but algae barn, but its been proven that algae barn cannot avoid pests and there are other good people out there, one day I will offer some for sale :)