Quikrete play sand invert safe?

It's fine. Just dustier and smaller grain size than swimming pool filter sand.
It will make your life easier if you wash it outside using a hose rather than trying to clean it inside in a laundry tub.

That said, check your pH over a week, before you put critters in the tank. Play sand and swimming pool filter sand are mined and shipped as locally as possible. The source in your area will not be the same as mine.
 
It's what I have in my tank, and I have snails as large as golf balls, so I think it is okay. Dbosman is right-- it is messy, but it makes a nice looking tank!
 
I agree with the comments. It should be safe, but messy. I had playsand in a tank for a while, but decided it was just too messy and kept getting in the filters. I highly recommend pool filter sand instead.
 
I have used it with Cherry Shrimp, Ramshorn snails, and MTS. Never have had a problem because of the sand. I would say that cleaning it before putting it in is probably a good idea. I usually just add the sand as it is and it seems to clear up pretty well after 24 hours.
 
[YT]a2plOlXhLtU[/YT]

i rinse mine longer, personally. i also only fill the bucket up ~1/3 with sand so i can turn the hose up more. he still has some murkiness in his which would account somewhat for buffering/ph issues.
 
Play sand isn't really messier once it is in your tank. It can look messier. With gravel, all the fish waste sifts down into the gravel. With play sand, it sits on top of the sand and is visible. I found that my tanks with play sand are actually cleaner than the ones with gravel. Since the waste is visible, more of it is removed during water changes. It's a little harder to vac. Not really harder, there is a different technique to vaccuming sand verses gravel. It just takes a little while to get used to it.
 
It's messier in the sense that it gets stirred up much more easily than PFS. Among other things, that means that it gets into your filters much more easily. I suspect you'll find play sand in your filters quite soon.

It's also harder to vacuum. It is very easily sucked up into your vacuum. Pool filter sand, because it has a larger and more uniform grain size, is not so easily sucked up into your gravel vacuum.
 
AquariaCentral.com