Why have a pool filter?

[EddieWalker]

I have a small 1,700 gallon pool that I fill up in summer and drain in the fall. It takes about 3 hours to fill it up, so I sometimes fill it and drain it several times during summer.

I've decided to use Bromine to keep it clear and stop algae. I'm also going to add a Nature2 system to it.

I currently have a 1/2 HP Hayward pump and a large filter system that a friend gave me. New filters are very expensive, so in the last two years, I haven't bought any. I was planning on it, but never seem to get around to it. Why do I need filters?

I have to baskets that catch pine needs, grass clippings, dog hair, crickets and whatever else falls into the pool. What does a filter accomplish?

My main reason to ask is that I haven't used it in two years, and it's so big that if I didn't have it, my view would be a lot nicer. I also don't want to buy filters. It's 3 feet tall and they seem like a huge waste of money. They also restrict the amount of water that my pump pushes. I had them the first year, and the got dirty, so I know they do something, but I didn't use chemicals then, and I am using them now.

What is the worse that could happen if I just took it out?

 

[MossRoad]

Well, if you haven't used it in two years, and things are fine, then what's the point, right?

Our pool is 12,500gallons - 24' round. We have a sand filter. Sand is cheap. I replace the sand every 4-5 years maybe. There's a pressure gauge on the side of the filter. I remember the setting in spring at start-up, when everything is clean. As the weeks go by, the pressure builds, and the outflow is noticeably less. When the pressure about doubles, I backwash the sand filter for 2 minutes, then rinse it for 2 minutes, then back to filter. I have to add about an inch of water when I do that, and makeup the salt back to 3500ppm. Usually about 10-15 pounds, so a buck and a half or so.

As the chemicals in the pool break down organic matter, the filter grabs it and holds onto it. Otherwise, it would just keep recirculating and settle to the bottom and make little piles of matter, and also the water would gradually get cloudy. The longer you go between filtration, or in your case, water changes, the better chance of some nasty organism building up in the water, and the less likely you'll have clear, clean, neutral tasting, non-smelling water.

So in a nutshell, the chemicals kill bacteria and organisms and the filter traps them so they don't recirculate and build up.

 

[bunyip]

We had a sand filter on the pool at our last place and the colour of the water when we backwashed it was disgusting, lot of body fats, hair and other nasties that you don't want to think about, the skimmer basket got a lot but not everything and certainly not soluble matter.

 

[EddieWalker]

Thank you, that makes sense.

 

[dodge man]

You will want a filter. It catches the fine contaminates that get in the pool. It keeps the water from getting cloudy. A sand filter is very common and does a good job. You just backwash it every few days and like already said, it’s amazing how dirty it is.

 

[riptides]

...It keeps the water from getting cloudy...

Fine contaminants.

I have a cartridge filter system, I backwash maybe, once a month.

 

[oosik]

You folks need to have a lake. No filters, no backwashing, lots of "natural things" swimming around. My little lake has 185 million gallons of water. Mother Nature handles it well. I tried it a couple days ago. Toe in the water - off the dock. Still too cold. It will be OK in August.

 

[gsganzer]

Eddie,
Maybe the filter you have is just overkill and something smaller would be better. They also don't need to run constantly. I just have a 6' stock tank (about 400 gallons) redneck pool with an Intex cartridge filter. I only run the filter for about 2 hours a day. I buy the cartridges in bulk at the start of the season and I probably go through a cartridge every other week.

 

[MossRoad]

We had a sand filter on the pool at our last place and the colour of the water when we backwashed it was disgusting, lot of body fats, hair and other nasties that you don't want to think about, the skimmer basket got a lot but not everything and certainly not soluble matter.

Yep. When I backwash it, I watch the color of the water. It's grey and nasty for about 20 seconds, then turns clear quickly. I generally only have to backwash just a few times a summer. Maybe 3-4 at the most. Then I drain the pool down in fall by backwashing and it's clean for next year.

We've had the pool for about 20 years. I've only changed sand twice now, and only because I figured I should, not any scientific reason.

 

[MossRoad]

You folks need to have a lake. No filters, no backwashing, lots of "natural things" swimming around. My little lake has 185 million gallons of water. Mother Nature handles it well. I tried it a couple days ago. Toe in the water - off the dock. Still too cold. It will be OK in August.

He's down there where it's hot, and has show dogs. There's been quit a few reports of dogs dying from ingesting algae in ponds that last couple years. I can see why he wouldn't want to take the chances.

 

[crashz]

Eddie - I'd keep the filters if you could. Or downsize them to reduce the footprint. For all of the reasons above, but also to keep the water clear with a minimum amount of chemicals. It will work with the chemicals that you use and the combo should reduce what you need compared to without the filter.

I run a diatomaceous earth (DE) filter in our in-ground pool and it significantly reduces cloudiness and acts as a "polish". My parents had cartridge filters and relatives have had sand filters and all worked well to keep the water clean, but I've never seen anything like a DE filter. Right now, my pool looks like 30K gallons of spring water.

But I had a learning curve with this thing. First year we made a lot of mistakes. First of which, I thought the DE filter sections were simple filters by themselves. So when we opened (the pool was closed for years) we vacuumed, removed the soilds, and shocked it. I ran that pump system for a week, dumped tons of chemical in and could not get it to clear. The water looked like green tea. So gross. Got some education, DE, and immediately it cleared within 8-10 hours.

 

[RalphVa]

If you use one of the perforated "safety" covers for your pool and all sorts of fine gook accumulates over the late fall, winter and early spring, you'll understand what a filter does when I performs a miracle and clears all that crap up. Well, first, you vacuum the stuff off the bottom on waste discharge to get the worst stuff. Then in 3 or 4 days, the water can be crystal clear, particularly if you either use a clarifier (makes the stuff float so it collects in the skimmer) or a flocculent (makes the stuff sink and accumulate so you can vacuum it up). Been doing this for 20 years here in Va.

On our NJ pool that we had for 20 years (it's still there according to Google Earth now 50 years later), we'd use an impervious cover and could have it swimmable in the same day we removed the cover because no crud got accumulated. Then the sand filter kept new stuff out.

Ralph

 

[txdon]

This was on the Austin news today as the water becomes warmer: "Dogs can become sick, and possibly die, after ingesting the algae or licking the algae on their fur. Symptoms include: . . . ."
Toxic algae found at Red Bud Isle, Festival Beach | kvue.com

 

[bunyip]

Haven't had a pool for about 20 years now but I recall being told that ideally you should turn over the water 2-3 times a day, our pool was 70,000 litres and we ran a 1.5hp pump fpr 8 hours a day during the summer, chlorine with stabilisers and salt, backwashed once a week or more if we had a big crowd in, our record was 30 o0ne day and the amount of hair in the skimmer was unbelievable, we also had a 'Kreepy Krawly' auto cleaner that found it's way around the floor and walls and did a good job of cleaning up bits that settled like dust and sand etc, replaced the sand at 5 years just as a precaution but could probably just have topped it up a bit but it was not expensive.
Never had a cartridge filter so cannot comment on those.

 

[kenmac]

I use to have an inground pool ..30,000 gallons of water 2 HP pump and motor.Had a pretty large sand filter.
I always used chlorine to keep my water stable.
As has been said, the sand filter traps all those body fluids, sunscreen oils, etc, the skimmer can't even think about catching

Since moving to the farm and selling the city home. I have a 30' round pool. It has a smaller pump and smaller sand filter.
This sand filter still traps the finer things.
All you have to do is back wash and you'll see in the site glass all the gunk the skimmer basket misses

 

[buickanddeere]

Chlorine does not work if there are particles of organic matter in the water .

 

[riptides]

Chlorine does not work if there are particles of organic matter in the water .

How so? Chlorine breaks down organics. That's why they recommend super chlorination or shock treatments.

 

[MossRoad]

Chlorine does not work if there are particles of organic matter in the water .

?????

 

[Industrial Toys]

As for the filter as it relates to my hot tub which at this time of year we keep cool to go for a mid day soak and debriefing session. It's comforting to know something is catching all that skin, hair and other bits and pieces that human beings tend to leave behind. It can be downrght disgusting when I wash it out periodically.

I noticed the eater turning cloudy last weekend and have to consult my notes on what to do. Generally just use bromine. At first I concerned myself with all the chemicals, and constant testing but found it wasn't really necessary. If the meat stays on the bones, tht's all that matters.

 

[dodge man]

You want the chlorine to keep the water germ free so to speak. It will cause organic matter to settle out of the water but that uses up the chlorine so to speak. The filter will catch a lot of this stuff and allow the chlorine to do its job.

One thing you are fighting with a pool is that it acts like a clarifier. If you have been to a water or wastewater treatment plant they have clarifiers. This is usually round and just slows the water down and allows solids to settle out, just like a pool. That is why an intake on the bottom of a pool helps so much, to pull anything settling out into the filter. It is also the reason you need vacuum a pool, to catch the stuff on the bottom. No filter and this stuff just keeps recirculating.