You'd be amazed at what is at the bottom/side of your pool.
I have had my pool up about a month and just bought a hose that will attach to my cheap scubber head that came with the pool (the kind you hook a water hose up to)
I have used it w/ just the water hose and tried to catch debris with the net and it got it decently clean.
My pool was pretty well clean (so I thought) when I vacumed it for the first time. I spent about 30 minutes vacuming it all over just ot make sure it was clean and then checked the filter. The filter was full of all sorts of nasty stuff I never seen.
So I'd say to keep your pool in tip top shape Id buy a vacume... even if its just a long hose that attaches to one of the cheaper cleaners.
I will be buying a better vacume later down the line, but this works wonders and can tell my pool even looks cleaner. Even tho before I thought it was clean
it came with a vac... i vacuumed after an algea bloom, and it was just coming back in the pool... i dont think my vacuum allows to vac to waste.. so now, the bottoms stays clean, not many leaves, dirt. etc.... i'm brushing it along with the sides... the only problem I have are all these dang freakin bugs.. the skimmer gets some, but i have to scoop most of them out. i can also see small particle in the water, but my water is still a little cloudy, so i'm thinking thats probably why.
I have the same pool set up as you do almost, and putting a knee high, nylon over the skimmer basket sure helped a lot with bugs, I get a lot of those swimming bugs that seem to be able to thrive in chlorine, but you have to be careful, because on the first day, I had so many bugs in the nylon that it almost shut down the pump! I have had some success also with keeping a pool noodle in the pool that gives the bugs something to get onto if they are stuck in the water.
16X48 Metal Frame Intex
6000 Gallons of water, (Rain has us just about completely full)
2000GPH Krystal Klear Pump Filter Size B Model 51
Hayward Aqua Critter Pool Vac (Somehow this works!)