well the tank was set up for 2 years prior to me getting it and I used most of the water and all of the sand when I re set it up at my house. Ended up having to do 6 200 gallon water changes 2 weeks in between each one to get all the levels down to where they needed to be so I’d say that was a challenge. But other than that it’s been fun. Jumping from 150 to 400 was intimidating at first but definitely glad I did it. Most of the fish will be able to live comfortably in this tank with out rehoming them cause of their size.