Mechanical filtration?

I need some advice.

My (first) tank has been running for about 9 months. It is a 20 gal with an 8 gal sump/refugium. It is filled with live rock, and about 1.5" of live sand (Garf Grunge). At this point there are 4 small fishes (2 blue-green chromis, 1 clown fish, 1 royal gramma), a hammer coral, a trumpet coral, and two bubble tip anenome. Cleaners: Astrea snails and hermit crabs. And of course lots of various little creatures that came in with the Garf Grunge including many small brittle stars, feather dusters, limpets, and I don't know what else.

I don't have a protein skimmer. I do weekly 20% water changes.

Everything seems to be healthy and happy. Although the hermit crabs seem have short lives.

At one point I was getting micro-bubbles in my tank, from the sump/return, and my LFS suggested I put a nylon sock over the end of the hose in the sump. This stopped the micro-bubbles. I cleaned the sock every couple of weeks. That was a chore.

Later I learned that a real white cotton sock would work even better. I bought a 4 (pair) pack at Target, and started changing them every week. I figured when I used up all 4 pair I would throw them in the washing machine.

That worked great and my water was REALLY clean. Each week the sock had a bunch of greenish brownish stuff in it.

Then I enlarged my sump and turned it into a refugium, and this eliminated the micro-bubble problem, and the need for the sock. But the sock was doing such a good job of mechanical filtration, and keeping my tank sparkling clean.

But then I wondered: Was the sock pulling good stuff out of the tank? Rotifers, copepods, I don't know, good microorganisms that maybe some of the filter feeders need?

I have since removed the sock and my tank doesn't stay nearly as clean.

To put a finer point on it: The sock was doing a pretty thorough job of mechanical filtration. Is that a good thing, or a bad thing?

Thanks reefers.

 

If you stay on top of maintaining them, as you seemed to have been, I think it would be fine. You prefer a real clean tank, I would go with that. You can always turn off your pumps and target feed if you are worried about the corals.

 

mechanical filtration is fine as long as its changed or cleaned at least every week . Twice a week is better. I try to never let mine go more than 4 days ...

 

I DO like a clean tank, but I am also really enjoying the little marine ecosystem that has sprouted in my tank. There are all sorts of neat things growing in there.

Would the mechanical filtration (sock) deprive those little creatures of food?

 

I suppose it would, not sure. But your pump impellers most likely kill them too unless you use an air-lift. So it's easy to worry too much here.