What am I actually filtering out?

[Thinking Cap Sideways]

Hi, everyone. I'm just happy to be here.

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I bought my house at the beginning of August last year and, since I was really busy moving and whatnot, I just continued to use the full-service pool company that the previous owner was using up until they closed the pool in October. At $240/month for the service plus the $60/month increase in power usage, I elected to figure it out on my own. The pool liner is getting long in the tooth but I'm sure I can baby it through the season; and I'd rather screw up on the old liner and not have to learn on a new one. So far, I'm doing fine. Thanks to the fine folks here I successfully opened the pool and had my chemicals straight within 3-4 days. I have a rather substantial leak that I'm working my way through but I don't think I need help with it yet.

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The thing that I can't really work out is what the filter actually takes out of the water. I understand the tree debris and pollen from the winter but what else is there to remove other than the wayward leaf or bug? I ask this because of the different filter types. My DE filter is supposed to be so much better than a sand filter but why? I brought the pump run time down from 16 hours/day down to 4 with no loss in water quality but why do I even need to run it at all other than to mix the chemicals and supply water to the vacuum booster pump (that I only run 2-3 times a week)?
Why couldn't I bypass the filter all together and just circulate the water or have a much smaller pump to do that like in an artificial pond? If I had an algae bloom I would need to filter those guys out after I killed them, but I won't have an algae problem if I keep the chemicals in order, right?

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What specifically causes the water to get cloudy if it isn't filtered daily?

 

[JasonLion]

Welcome to TFP!

There is a constant stream of fine debris falling on the pool: pollen and dust mostly, plus there is always some dead algae in the water. If people are swimming there is lots more, dead skin cells and dirt people carry into the pool. This is a slow process. You can go several days without filtration, but eventually the water gets hazy and does not normally recover without filtration.

 

[Thinking Cap Sideways]

Okay, so what are the downsides to only filtering every other day or every 3rd day? I notice that there are plenty of leaves and bugs on the surface that don't get taken care of because the skimmer doesn't run. I have a single-speed pump that's almost brand new so replacing it with a multi-speed pump seems foolish. I envision a little solar-powered pool Roomba contraption that floats around and skims the surface all day but I have yet to find such a critter.

 

[JasonLion]

You need the same amount of filtering, regardless of when it happens. The best thing you can do is spread that run time out so it comes in many fairly short blocks around the clock. That way you get as much of the floating debris carried to the skimmer as possible, rather than waiting around until it sinks. You also need to add chlorine daily, and it takes some pump run time to mix that in, which might as well get used for filtering as well.

 

[jblizzle]

Well, then your chemicals will not be mixed throughout the pool either. And the FC may drop too low in areas allowing algae to start.

Why not just run the pump for 2-4 hours every day?

 

[Thinking Cap Sideways]

And that's exactly the type of answer I'm looking for. I'm sure it's going to be up to personal preference but I'm trying to avoid problems like the stratification issue that ↑↑ brings up.

The power company cuts me a break if they can install a box that shuts my water heater off in the heat of the day. If they give me the same deal on the pool, would there be any downside to filtering in the dark?

 

[jblizzle]

Not really. Many members only run at night due to electrical discounts. If you could run right at the start and end of the lower price period, that would keep things mixed.