ruck'n'reefer,
Have had sandbeds in several tanks over the years. While there are critters in the sandbed that eat detritus, ummm, well.... what do you think they do after they eat and digest that detritus? You got it - they make more detritus
Have moved plenty of sugar sized aragonite sandbeds from one tank to another. Those sandbeds were disgusting in the amount of detritus they held
Having had three BB tanks for the past year, I don't think I will ever go back to having sandbeds.
Alan,
Nope, no skimmers anywhere. I don't think having a skimmer would do much for the detritus on the bottom of the tank, though. We do have pretty good water flow from powerheads placed near the water surface in all tanks, but all the flow really seems to do is move the detritus to lower flow areas rather than lift it into the water column. At least that's how it appears to me, and that's why we baste under the rock to move the crud to the back of the tank, then do a second siphon.
The only time detritus is in the water column is the day before water changes when I clean the glass then turkey baste the rock. Lots of crud comes out of the rock and clouds the tanks, some of which ends up on the bottom, some in the filter media, and some probably right back onto the rock.
We had a Precision Marine HOB-1 skimmer, as well as powerheads with foam in the prefilters, on our very first tank - a 75g way back when. Had lots of skimmate from it, but then we had a pretty big bioload in that tank compared to our current no skimmer tanks. Also cleaned the foams weekly, sometimes in tapwater, sometimes in changewater. Used RO water in that tank.
At one point, we began to have a cyano problem in the 75g. I had read about basting the rock and sandbed to help export the accumulated crud that was causing the cyano. Man, I gotta tell you, basting rock that had never been basted made the tank so freaking cloudy we couldn't see to the back of it
Anyway, once the tank cleared, I removed and cleaned the foams, then basted the rock some more. I also gently basted the sandbed where the cyano grew, not so much as to cause a sand storm, but enough to loosen the cyano and some of the detritus into the water column. When the tank cleared again, I cleaned the foams again.
I did this basting and foam cleaning thing at least twice a day for almost a week. Cyano problem went away, but I kept up the weekly basting before the water change and foam cleaning and cyano wasn't much of a problem after that.
So how did the skimmer perform during all this rock and sandbed basting? Well, I can't remember, so I just phoned Chris, my main man
, who was in charge of skimmer cleaning. He seems to remember that there was a slight increase in skimmate but nothing as major as one might think.
I hope my long, convoluted story helps answer your question