I hate coco husk. It sticks to my hands and it doesnt come off even if I fling them off. SO Iam assuming it may bother the frogs too? Anywho. The background I was thinking id glue gravel or larger rounded river rocks. I guess its what I have lying around. But if I used coco husk as a background it would get mildew and all that fungus junk. Actually you are right I do have filters. But the ones I have are pumps, and powerheads. My other filter broke down. :/ So I need to get another whisper.