I have a leveling issue

[Big G]

Solid plastic shims? Ok, I'll look into it. What about the back of the aquarium? My tile sucks, it pops up in some spots while in other spots it's lower and makes absolutely zero sense. I can't make alterations to the tile as I am a renter. Thanks for the help!!

For tighter gaps, I find that if I cut up one of those plastic cutting sheets for the kitchen into strips, I can stack them like cards and get a nice tight fit on ceramic tile floors.

 

[Big G]

Solid plastic shims? Ok, I'll look into it. What about the back of the aquarium? My tile sucks, it pops up in some spots while in other spots it's lower and makes absolutely zero sense. I can't make alterations to the tile as I am a renter. Thanks for the help!!

If your tile floor is that irregular, you could consider using shims and placing a yoga mat under the tank stand. I've had the same problem in the past, and by using both, I got a real nice stable tank. Make sure to put a "level" on the top of tank to ensure a truly level tank. Doesn't make much sense to shim the tank and it be leaning one way or the other. Especially if you are in earthquake country. Level is "good."