Not Enough Space

It started out as a simple enough encounter with a customer.
Where she wanted to know how the Under gravel filters work within a fish tank.

Which...honestly...I have no idea. I know you place the grate at the bottom of the tank, cover it with gravel and place the tubes on the side and walla! 
I also know you have to clean out that grate every few months or so as it gets clogged. 

And so I told the customer as much.
And instead recommended that she get an over the back Tank filter because those are easier to deal with. 
To which she stated that she already had one...only she wasn't using it because when she set up her tank (it was a corner 56 gallon) she'd placed it too close against the wall so the filter she bought wouldn't fit in the tiny gap that was left.

-Which I was like...why not readjust the tank to let it fit if you already bought it??? 

But I just went and suggested some internal filters that could suction cup to the inside of the tank and not need to hang over the back.
The problem?
We were out of the larger sizes. We only had ones left for 10 gallon tanks. 

And the customer was like "If I buy this smaller one now, will it help until the larger one comes in?" 

To which I had to be like..."Yes...it will help a bit, but the larger one will do a better job."
"Well, I'll get this one for now." was her response.

And then. THEN. 
I find out that her water is green....which is possibly due to no filtration, or direct sunlight or who knows what else.

AND.
She ALREADY HAS FISH IN HER TANK.

Seriously?!
SERIOUSLY?!
She was like "Sooo I bought these fish here" *points to goldfish* and I already had one die....

And I was like: ITS BECAUSE YOU DIDN'T HAVE A FILTER, WHY IN THE WORLD WOULD YOU PUT FISH IN A TANK THAT BIG WITHOUT A FILTER?!

Because, especially with goldfish, you'd be needing to do water changes at least once a week to try and keep that water clean, and goldfish are sooo messy...it's like...crazy that she decided that she didn't want to adjust the filter or move the tank or worry about anything until AFTER things started going wrong and GAH.

It doesn't help that this customer only told me this information...After she bought MORE FISH.
>.<

-Sarnic Dirchi