'Automatic' pool cleaners.

For anything to do with the garden and pool
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Renaud
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'Automatic' pool cleaners.

Post by Renaud »

Thought I'd make this a seperate post to help anyone that is new to the'automatic' pool cleaner world.
For information: there are three main types of automatic cleaner.

The first is the type that uses your existing vacuum system. You plug in the vacuum hose as usual, but you add a strange looking 'brush' that looks a bit like a giant orbital sander. The 'brush' or vacuum head is designed so that the water being sucked up causes the head to move around by itself.
Advantage: low price, good for smaller pools.
Disadvantage: tend to get pushed away from the refiller jets, still feeds dirt into your filter. Extra strain on pump.
From 180 to 500 euros typically.

The second type is also powered by water. But now its usually a device on wheels, with its own filter bag. Polaris seem to be the biggest maker in this category. At the lower end of the range you simply use the water flow from your existing vacuum point. But as the models get bigger you will need to install an extra pump dedicated for this purpose.
Advantage: Modest price if no extra pump required. Collects dirt into its own bag.
Disadvantage: Bigger models may need extra pump. If you want to use in another pool, you will need another pump on that pool. Smaller models may not climb pool walls.

The third type is usually described as a 'robot'. This is totally independent of your existing filtration/vacuum system. It usually runs on two rubber 'tracks', like a little tank. Inside is a motor that turns the tracks to make it go forward or back. This motor also pumps water in through the bottom of the device, which is close to the pool floor, and up through an internal filter bag and out through the top. This flow of water pushes the robot against the pool surface as it moves. In this way it is able to actually climb the sides of the pool too. A brush at the front and back help to clean the surfaces. It is powered by electricity from a supplied 12 volt transformer, via a floating cable.
Advantage: All dirt goes directly into its own filter bag. Cleans sides and water line. Can be run regardless of whether pump is on or not. Completely automatic.
Disadvantage: Most expensive option. Typically 1200 euros and up.

As always, the more expensive options tend to give better results. I've chosen option three, as I've got 2 large pools to clean, and I don't want to be dogged by back problems in my old age, due to pushing that poll around all day! Also I like the fact that all dirt is taken directly out of the pool, thus lowering the work done by the main filter. Also there's no extra strain on the pump caused by having to also power a device around the pool. And then there's the novelty factor: guests are always fascinated to watch the little blighter trundle round working hard, while I'm not!!

You should not allow swimmers in the pool when any cleaning device is present. Hoses and cables mean a risk of entanglement. I am going to invest in a sign to place beside the pool to say "Pool currently closed. Cleaning in progress". This is quite important if you want to leave your 'automatic' cleaner unattended.
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Alan Knighting
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Post by Alan Knighting »

Renaud,

My immediate neighbour has your option 3. In the past he tried options 1 & 2 and discarded them both as being ineffective for anything other than removing leaves, etc.

The device he uses is large because it contains large pleated polyester cloth filters, similar to those used on car engines, which are capable of removing debris down to just a few microns in size.

He is delighted with it.

As you say, put it in the pool, plug it in, switch it on and off it goes - in any pool you like, anywhere you like, anytime you like!

Regards

Alan
Jayjan
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Post by Jayjan »

If you vac your pool to waste through your filter you dont get a dirty filter the only drawback is keeping the pool water topped up. We have had a pool in Uk at our home for 15 yrs and have been put off using automatic pool cleaners because of the mosaic tiles have been advised they losen the mosaics so always used the old fashion method but vac to waste to save your filter getting mucky. We still use the old fashion method also on our pool in Portugal. Regards Jayjan
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Alan Knighting
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Post by Alan Knighting »

Jayjan,

Whilst on the face of it backwashing to waste sounds like an efficient way of keeping a pool clean it is not the answer on a daily basis. Apart from the obvious problem of excessive use of water (that is a huge problem in times of water shortage and hose pipe and pool topping up bans, as is now the case where I live) there is also the question of the efficiency of your filter.

At first, a high-rate sand filter with clean sand will remove only larger particles (between 12 and 15 microns in size). As the dirt builds up in the sand, the filter will remove finer and finer particles, eventually down to submicron size. In other words the filter becomes more and more efficient, up to a point. That point is reached when the pressure guage shows an increase of 5 to 8 psi over the pressure when the filter starts up after being cleaned. Backwashing too frequently does not allow the filter to do the maximum cleaning job and you are not improving filtration by backwashing before the appropriate pressure rise is registered.

Regards

Alan
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Renaud
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Post by Renaud »

Jayjan, "vac your pool to waste". Goodness, your water must be unmetered!!! At the rate my pump works I would have to be very quick with a vacuum hose!
Pumps seem to range from flow rates of about 9 cubic metres per hour to more than 30. A mid range pump of around 20 cubic metres per hour would pump away 5 cubic metres in 15 minutes. So I'm assuming that you would only advocate this strategy for vacuuming any areas where there was a visible accumulation of debris. However, you will still need to backwash the filter anyway, so your strategy would inevitably result in high water consumption. Just as a clarification, I'm assuming that you do not really mean "vac your pool to waste through your filter". Pumping to waste would by pass the filter. Pumping to waste through the filter is 'backwashing' and you should not be vacuuming when doing this. I'm sure you know this, but mention it in case others, not so familiar with the terms, get the wrong idea.

Alan, yes getting the frequency of backwashing right is tricky. Your point about dirt actually helping the filtration process is a good one, and is not often mentioned. The only comment I would add is that some of the 'dirt' will be organic matter. This could be bits of grass or leaf fragments etc, or small insects, and other animal matter. All the time that this material is in the pool system it is burning up chlorine unnecessarily. Backwashing frequently will prevent this, thus leaving more chlorine available to do its job in the pool. But this will also wash out the mineral (non-organic) matter in the filter which, as you say, is actually contributing positively to the process. As so often it's a balance between a number of factors that will vary from pool to pool.
Jayjan
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Post by Jayjan »

Hi Folks I am fortunate in the Uk that my water is not metered, but I still pay a hefty bill of approx £650 per annum . Vacuum to waste does require alot of water to be put back in pool, the water level drops about 3 inches on a full vacuum of the pool. but I am also lucky that my pool is indoors and doesnt get a great deal of muck in it. I never backwash my filter unless the reading is up to 0.8 bar or above. Renaud the pool company I deal with in UK tells me it will do no harm vac to waste as it by-passes the filter altogether or is he spinning me a tale? My pool in Portugal is only small and due to water shortages this summer we have been using the normal vacuum method. Alan what size is your filter mine is a 24" with the multiport valve on the top, I think thats the most popular one for most pools so I've been told,( I know it depends on the size & gallonage of water of your pool) we are thinking of installing a new one in the Uk as it is now 15 years old and the spring on the multi port valve is not as good as it should be so it tends to act strange occasionally. Regards Jayjan
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Alan Knighting
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Post by Alan Knighting »

Jayjan,

My pool is 12m x 6m with an average depth of 1.75m, maximum depth 2.5m, so contains approximately 125m³ of water.

The sand filter is a Hayward S-301T. The shape is basically that of a ball with a width and height of 33". The flow rate is 102gpm, the maximum working pressure is 50psi and the filter area is 48ft². The 6 position valve sits on top of the filter.

Incidentally, I changed the sand at the begining of this season with remarkably benefecial results. The old sand had developed some chanelling and numerous mudballs, problems which can not be dealt with by chemical treatment or backwashing.

Regards

Alan
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Ciapolin
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Post by Ciapolin »

Jayjan - wow you are lucky! In the UK we had to have a meter because we had a pool! I guess it depends where you are.
Carole-Anne
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Alan Knighting
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Post by Alan Knighting »

Carole-Anne,

Putting aside the capital cost of building and filling a swimming pool, I think the runnings costs are hugely exagerated by those who don't have them.

I think the cost of electricity, water and chemicals (a few hundred pounds a year in total) is insignificant compared with the benefits of having a pool. For me, the annual cost is less than paying for SkyTV for a year.

Regards

Alan
Jayjan
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Post by Jayjan »

Thanks for reply Alan. My present filter is a tagelus filter area 0.17m2 Max operating pressure 2.5bar & flow rate is 8.5m3 per hour. My pool in Uk is 10m x 3.5m so your pool is quite a lot bigger than mine it holds approx 9000 gallons. My pool in Portugal is only a small one approx 4500 gallons kidney shape but is same depth all the way through. As regards running cost I too find it quite reasonable the only big cost we have in the Uk is the Gas boiler to heat the water as we use it for Hydrotherapy for our disabled son but chemicals etc are only a small cost & find the pool tablets are more economical than granular chlorine. Regards Jayjan
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Ciapolin
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Post by Ciapolin »

Alan - I agree totally. In fact we used to purchase our pool chemicals in 'neat form' through the family engineering company at almost half the price. Of course it wasn't nearly as convenient as pool specific chemicals, and a little more dangerous!

You are right, the most expensive thing was filling the pool after we changed the liner, but on a positive side we got a discount for water 'disposal' (I think 5%) because of the evaporation effect.
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Marion
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Post by Marion »

We have a pool of two halves. It is L shape with the smaller area roughly about 3 feet deep and the larger area 6 feet deep. There is a vertical drop from one area to the other. Does anyone know if an automatic cleaner would manage to climb/descend between the two area, or are they just designed for pools with sloping floors?
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Alan Knighting
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Post by Alan Knighting »

Marion,

The Polaris models come up to the surface on a regular basis and therefore would certainly handle both levels of your pool with no problem.

Alan
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Post by aillis »

I bought a robot on the web from the states for around €1000 has big washable filter the pool looks much cleaner and uses less chemicals and needs less backwashing so am well pleased as the only robots I had seen in france were €2000+ !
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Renaud
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Post by Renaud »

Marion,

A robot cleaner powered by electicity (via a low voltage transformer!) will certainly climb vertical surfaces. My only doubt in regards to your own pool is that as the cleaner moves over the vertical drop it may 'leap over the edge' and not actually climb down it. It will, however, climb back up this surface when it meets it during its random wanderings. Might be worth bringing this up with a supplier specifically when you get to the purchase stage.

aillis,

Yes, I looked at buying from the U.S. on the internet. I even had quotes returned from some e-mail enquiries. The basic purchase price was considerably lower than in France. However, you need to add in shipping and TVA, and possibly duty. This makes the situation less attractive. Also you have no effective guarantee, and servicing could be tricky. There are quite a few models available in France now for between 1000 and 1500 euros. Which, for the work they save you, is a bargain!

Jayjan,

Yes your pool company is correct in saying you will do no harm in vacuuming directly to waste. It's just that in your original post you stated "vac your pool to waste through your filter". If you vac direct to waste the filter will be bypassed. I only pointed this out in case someone thought they should do it through the filter. Big difference!
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