If everything and everyone is fine, don't worry about it. You will suck up dragonfly, snail and salamander babies. Mulm does not mean parasites or bad things. You can stir it up a bit and let your mechanical filter remove it.

I have the same mulm or detritus that only clouds the water if you move something or stir the water or get in and create a wake.

buyorsell is approaching it the same way I have. I've decided not to do any vacuuming.

I've always thought about how clean and easy it would be to buy an expensive Pondvac III or something... but I think in the end I'd just get tired of using it,then having to store it for six more months. Ughh.

For three years now I've let it be, and the water always clears plus I'm told by the experts at the local aquatic gardens that the fine carpet algae on the sideliner is desirable.

I'd like a black liner beneath the water surface to show but ecologically I guess the fine algae layer with the little bits of mulm is better.

I could try stirring it up and cleaning filters more often, as suggested,...if I was more motivated.