New Filter Installation TODAY.. questions

Hello. Had some multi valve and lateral problems and decided to just buy all new.. and go with a bigger filter. (my pool: 24ft round, AG). Went from 18 inch filter to 24 in filter. Running a 1 hp pump.

Anyway.. the filter arrived yesterday. Everything seems to be there.... but instruction manual is somewhat vague. I have read here and watched you tube videos on filter installs, sand replacement, etc etc.. So I think I have a pretty good understanding of the procedure. But, as usual.. something comes up that I am not sure of.

FIRST: The laterals on this unit do not fold up.. so you must put the main shaft inside the tank then attach the laterals. Theres no mention of correct lateral installation in the manual. It seems that these slide in.. then a quarter turn to the right.. is that it? They are not loose.. but they don't screw in tight either. I guess the sand holds them in place? Or am I missing something?

ALSO: This was in the box.. just kinda loose.. anybody know what it is.. or what it's for? Looks kinda like a mini vacuum hose you would use in an aquarium.. odd.

http://www.hometownsitedesign.com/po...lterparts1.jpg

close up of end:
http://www.hometownsitedesign.com/po...lterparts2.jpg

I believe that is 'air relief tube'. The tube end should be plugged into a fitting near the lower pipe assembly and the upper end, with the white plastic 'knob' should be as near as possible to the top of the filter. The purpose is to provide a way for extra air inside the filter to be removed so allow the maximum amount of water to be in the filter.

Without this you will have to regularly drain excess air from your sand filter...with this properly installed this problem is largely eliminated.