....if that tank is nothing "special" then sign me up because I think it looks amazing.
That being said...
when you are having this much trouble making the decision it is because you probably do still like it on some level and or/ you have an emotional attachement that is still lingering.
It is best to not do anything when you can't decide.
Try to figure put what is it that is holding you back? Is it that you love the way it looks? Is it because you spent so much money on it over the years? Is it because you have started and stopped the hobby before only to start again later? I think you have already thought of all the reasons why you should you just need to stack up the reasons why you shouldn't on the other side and see which makes more sense. (I am gessing that was the purpose for the post)
I say, don't worry so much about the future. If you want to take it down, then take it down. Sell it and use the resources for another hobby. If you want to set up another one in the future you can do that.
Of course right now (while you are thinking of getting out of it) you feel like you would never start it up again...but that may not be the whole truth. You are looking at it from a perspective of it wearing on you. You might not always feel that way but if you do change your mind you will have a new entusiasm all over again and probably want different things then anyway.
You should think about what would benefit you the most and bring you the most joy in the here and now. Let tomorrow (or 10 years from now) take care of itself.
As a busy mom of three I completely understand trying to make time for everything and something has to give. If you are not feeling the love then don't waste your time and energy on it. Send it on to bless someone else and bring someone else joy.
Just my two cents.
You have to live for today...