Need some advice... Tank not doing well.

[Oxymoron]

Part of me was worried about hearing that while another part is relieved.
With recent changes to my job, I will be around town and be able to maintain the tank on my own as intended.

I have a dream of upgrading to a 6 foot shallow tank and have already started entertaining the idea.

But If I can save this setup and possibly trade it or sell it I would rather go that route then tear it down?