the small 5 gallon work great so does the 10, as far as filter goes never used on e and never had a problem. Not to confuse you or anyone else fo that matter they do have different colored valves. It is my belief if you have yor hose made at the gas company like I did to get the larger valve. I think it's red and black in color. the part that screws to the tank. Reason being is that it gives better flow in sub degree temps. I learned this the hard way. Good luck to you.
What you are referring to is called a QCC fitting. The colors are to allow quick determination of BTU rating of connector. Black 0- 100,000 BTU Green 0 - 250,000 BTU Red 0 - 450,000 BTU.
I don't know if these colors and ratings are industry standards or not. If you look on the end of it the rating is usually stamped there (100k etc.). I have seen one that was rated for only 35k but don't remember the color.
The next issue I have had to repair (more than I care to count) is, the QCC fitting has a built in excess flow. Basically its a small bearing and spring inside that will stop gas flow if the flow is greater then the rating allowed. This is for your safety.
To know if your fitting has this hold it up to a light source. If you see light it doesn't have one.
Only problem is some manufactures use a cheap metal ball bearing that corrodes if any moisture gets inside it (see a problem here), which in turn will not let any propane through.
This probably explains most the posts on this site about problems with the hose or not getting any heat out of propane......
