Refugium Substrate

Ok, this topic is covered quite a bit here, and I've tried to find this answer but can't.

Should I or Should I not cover the kitty litter/clay refugium substrate with a layer of sand?

Thanks!!!

 

I Don't think it really matters?

 

I would cover it.

 

what about depth - 3-5" of mud and 2" of sand, or another recommendation?

 

the depth is a function of how much anaerobic bacteria you will be keeping.
typically below 4 inches it is mostly anaerobic

 

Just to make sure I am reading this right.

The first four inches of depth is mostly aerobic, and any sand below that is more anaerobic.

Aerobic activity breaks down ammonia and nitrites while anaerobic breaks nitrates down into nitrogen gas.

Did I get that right?

 

the instructions on the last jar of mud I bought said to put a 1/2" layer of fine sand over the top.

 

That sounds correct to me.