Seal it! While it's not harmful it will clean a LOT easier if sealed and it prevents discoloring as well. Plus does Google know you are using it for a reptile and not some floor? Many here will tell you - SEAL IT!
I believe this sealer works well. It is water based and seals both grout and tile. Someone please correct me if this is not safe. I intend on using this for my bearded dragons tiling job I plan on doing this weekend because I heard it is a great product:
I just set Swordtail's timer for his bath and paused it so I could actually fill his soaking bowl up and he crawled over my phone and canceled the timer
Mirage came out of brumation on April 26. He was doing great. On May 2 he started acting funny. We just redid his tank, and he keeps going into one of his hides. He just lays there. He shows no intrest in food. HELP!