Is there any decor that could be sharp? Like the inside of his cave? No, everything is smooth.
Does your tank have a filter? Yes, it does. I have the Aqueon Mini Bow tank.
How often do you do water changes? I do 25% every week.
And what percentage?
Can you test your water? If not, take a sample to the pet store *before* you do a water change and ask for the exact numbers for Ammonia, Nitrite and Nitrate. They'll try to get by with saying levels are "safe" or "okay." Insist on the numbers. I should probably invest in a test kit. The only pet stores I have nearby (45 min away)
are PetCo and PetSmart. Do they test it there?