So after months of using my current at water container, I was having problems with the amount of actual water it held. So after some brainstorming I thought about using acrylic tubes mounted inside my old larger container so I could maximize water capacity but still have my dosing chemicals contained in it..... So after a quick visit to Saco polymers I put these together... 
They hold just under 2L each and I decided to not attach them to the tank but to leave them mobile for ease of cleaning and refilling. 
Here they are installed.... 

Not a great pic sorry. 
So my water capacity went from about 5gal to about 30g a much needed increase.