Just bought a used tank off someone, 40 gallon 36 x 18 x 16, for a beardie i'm bringing home mid August. There's a good amount of calcium deposits on the glass and there was bugs (I've rinsed and scrubbed it out with lysol). I've done another round of scrubbing with vinegar but some of it is still not coming off and I'm not sure if the tank is 100% safe. I wanted to do a round of bleach solution too but not sure if it can harm the beardie if I won't be using the tank for another month.
Vinegar & baking soda with a kitchen scrubby might help. That's a good cleaner, I use it for the kitchen sink, shower doors & shower heads to get off mold & soap scum off. You could try spraying the vinegar on first & then some baking soda on a scrubby. Wear some gloves.
When we first four our used tank I did was it with bleach and dish soap all over and then washed it, we let it air out and dry before bringing it in the house, once it was in the house and all ready I wiped it down with some vineger and water solution.. my girls are totally good but I'd give it some time to air out properly so theirs no chemical smell, and make sure you rise it super good of course.
Thanks for all the replies and suggestions. I've done 2 scrubs with a 90/10 Vinegar/water solution and then a scrub with Lysol with bleach. Most of it's gone but there's still some stubborn places which I'll do 2 more scrubs for. What I was concerned about was after even all the calcium deposits aren't showing, I'm sure there's still around the tank and I don't want that to affect my beardies health.