I have an IG pool, so others can help you better. Same principles apply.

There are 2 aspects of cleaning a pool, 1) Keeping visible crap out, and 2) Keeping your water balanced. The 2 aren't very related.

As for the 1st goal, you can just look at your pool and assess that. All pool cleaners are just designed to keep and remove visible crap out of pool. If you have any type of automatic unit that does that, fine. Even with many, you still might see stuff that lingers and you can either vacuum it out, skim it out whatever. It's not rocket science. Brushing is used to get the crap sticking to the walls off of it, and vaccuuming is to get it out of pool. Skimming is to get it out before it falls to bottom. If you have cleaner doing what you need fine, if not, do it manualy or get another cleaner. It's personal preference and it all requires some work regardless. In any event, this aspect of cleaning a pool is all visual and invloves removing tangible items. You can see for yourself how it is going.

The second goal is balanced water. There are many websites discussing what that invloves. Bascially, it is all a matter of keeping a nice amount free chlorine in our pool, along with the understanding that an unbalanced ph affects the effectivenees of the chlorine. As a practical matter, failing in this area shows up by having algae in your pool, and typically dark green water from the algae. Also, keeping water circulating helps in getting O2 in the water, mixing things up, and keepign water clean.