I would absolutely NOT use a roughneck trash can. I had 2 of them pop the seam at the bottom. The first time I thought I had maybe dropped a rock on it (used it for cooking rock... had about 15 gallons of water leak onto my upstairs floor and down through my ceiling).
The second one popped just sitting in my closet not having touched it for days. I only opened the closet because I found the floor outside the closet wet. Opened the door and a nice little stream of water was shooting out of the bucket. Good thing I didn't go into work that day or there would have been almost 30 gallons on the floor by the time I got home.
Since these incidents, I dropped a bit more money and went with the Brute cans (most of the containers I found in the size dimensions I needed at the time were 4x expensive). The Brutes are thicker and the spots where the molds fit together do not line up on the can. This is hard to explain, but take a look at roughnecks. Their seam around the bottom of the can is the same height on the inside and outside of the can and this creates a weak point. Then, look at the seam on the Brute. On the inside it is much higher than the outside. This way, any inconsistency in the way the molds line up does not result in the same kind of weak point where the wall can just sheer from along that "score line."
I've tested my water from time to time (especially after sitting in the container for a while) and have never tested phosphates. On the other hand, who knows what else they could be leaching. In reality, I think you could be facing that problem unless you use glass, but glass is usually not going to be cheaper or safer (in terms of breakage) unless you've already got a tank and a safe place to put it.