Im currently in need of a new substrate for the bottom of my 55 gallon fish tank that has been up for serveral years.It is currently home to mollys,guppies and chinese algae eater their old substrate had gone old and bad(a mix of gravel,sand & aquatic soil)im also low on money so I was wondering if I could use anything I had at home.I have diatomaceous earth( food grade),Perlite(waterlogged),cypress mulch & play sand(ive used i the past and it had no negative effects on my tank).If I can use anything I currently have please let me know.