Only if you put on moss.
I found something better than this I think. This year I topped off with very fine akadama (1-2mm) . Then I used dry powdered green moss and treefern fibre chopped very fine and spread a thin layer over the aka. The moss seems to grow nicely on the clay.
No more sphagnum. It looks very neat like this. Good enough to exhibit and the moss starts to grow in a couple of weeks. You will find it difficult to find tree fern fibre so you need to find something else. Maybe screened compost or bark will work but as long as it stops the akadama from being washed away.
If you water gently with a fine watering can like the old Japanese, then all you need is powdered moss but who does that now days??