Plastic in tank

[ickmagnet]

I was wanting to put a plastic tupperware container in my tank to use as a frame for my rock setting. Would this be harmful in anyway?

Also, please help identify growth in my earlier post titles "What is this stuff". I dded pics now.

Thanks!

[ickmagnet]

sorry please ignore. Double post

[fkshiu]

The plastic will last longer than your tank will and even you. That's why you should always recycle plastics - it just hangs around. ;)