I don't recommend Tesco playsand. I used it when I first set up my tank a year ago (because I buy it for my kids sandpit anyway) and I found it to be VERY fine and tightly compacting.
To be fair, I've never tried Argos playsand so I can't compare them directly, but I assume from other positive reports that Argos playsand is slightly coarser and more suitable.
I use tesco playsand for my hamster to roll around in as it is softer than regular pit sand and I have Argos sand in my tank can't fault it... was cheap and my cories love ir