Fintastic!
Fishaholic
I think I read somewhere here that children's playsand from Argos is ideal for aquariums, is this right? Does it need to be treated/washed before it goes in? I'd like to switch from gravel for my corys. 
Good old Argos play sand. As others have said, give it a thorough cleaning. Lots of silt and bits of wood etc. I ended up losing around a third of the bag just through cleaning, but I may have gone a bit OTT.

The crud that collects on the floor of the tank![]()

A third? Blimey, OCD?![]()
I started out one of my tanks with Argos play sand and it caused no ill effects to my fish whatsoever, when I eventually added them. I had probs with cloudy water probably through inadequate rinsing but a couple of very large water changes sorted it. In the end though I switched to gravel because the sand was going straight up my siphon vacumn during cleaning.