Yes, you can use playsand. Should you? Almost certainly not. First, because it is silica based, not calcium based like marine sand, it will offer no buffering capabilities whatsoever. Another problem with it is that it was sharp edges that can irritate bottom dwellers and sand sifting organisms. It has also be sand that it can contribute to diatom blooms although I can't personally vouch for that one.
If you are going to set up a system to properly care for your intended list, spend a few more dollars and get the right stuff. No need at all to spring for "Live" sand, but the benefits of aragonite far outweigh the extra cost.