Refugium question

How thick a sand bed in the refuge should I use? Also do you desturb it or leave it alone? I was thinking you don't mess with it cause you want all the pods and stuff to multiply. But then why do you clean and stir the sand in your display tank?

i too am curious about this.

Not everyone cleans the display sand. I don't. I won't. For a fuge, at least 5 inches(of your going for dsb) and do not stir it.

Cool, thanks!!!

Taking into consideration that you understand the nitrifying bacteria's responsibility of converting ammonia (NH3/4) into nitrates (N03). a DSB (deep sand bed) takes it a step further and offers the benefit of reducing/removing N03, but not without risk.

Because the sand bed is so thick, it develops layers in which oxygen is present. Of course the further down you go the less oxygen there is. Let's categorize them into 3 separate layers, the oxic, hypoxic and anoxic zones. The top being oxic full of oxygen which supports the aerobic (nitrifying) bacteria. The hypoxic layer foster a different bacteria called anaerobic (denitrifying) bacteria. It's job (in the DSB) is to take the nitrates from the tank and convert into harmless nitrogen which is removed by agitation on the surface of the water.

The risk involved with the DSB is the anoxic layer which creates hydrogen sulfide and sulfate (rotten egg smell). This layer can NOT be disturbed, if you do it will release those toxins into the water column and eventually kill all living organisms in the tank.

So if you decide to use a DSB in your fuge know the risk involved.

All I have to say is sisterlimepot hit that one on the head great explanation of a bsd. Just say a lot of people try to stay away from bsd for that fact that if you do disturb that layer it will wipe your tank out and two there is another possibility that your bsd and die and end up wiping our tank out.. Bsd are very  but you need to know what your doing to keep it healthy.