Changing filter media in pool filter - how often

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Re: Changing filter media in pool filter - how often

Postby jazzman » Tue Oct 29, 2013 9:46 am

Greenside wrote:Our pool sub-contractor asked if he could change from the Astral pump in the original spec to a Kripsol Koral-KS.
The pool is 45m³ including a spa in one corner that overflows into the main area. The pump room is about 9m away from the pool and attached to the house in a room with extra insulation in the walls. Both pumps proposed are 1.5HP single phase and I expect to have to run the filter 6 or 7 hours a day.
It looks to me as if 3 phase is worthwhile (we have it) but I'm told that only larger pumps are available in Thailand. True? Can they be ordered specially without too much headache?
Kripsol seems to be a well known supplier in Europe - anyone got any experience of their products?

I've copied above some comments from an earlier post of yours in another thread.

Filter media
First, I recommend checking out these links: ... olsand.htm ... lbrite.pdf ... _en_de.pdf ... -Media.pdf

Do bear in mind that what you will read from the manufacturer on any product contains of course a lot of marketing hype and it will be up to you to decide whether you want to use crushed glass or zeolite (Zelbrite™). What I can say after 13 years experience with Zelbrite and 8 years experience with crushed glass (DiamondKleen™) is that the water in the pools is crystal clear with pumping times much reduced from those needed for sand, and over those periods comparing the pools, I have not seen much overall difference. Backwashing is also less with these products, and the quantity required is only 75% by weight of the sand that would be needed. Do bear in mind that most pool owners tend to backwash far to often which results in a significant loss of water and all the precious chemicals in it. Sand that is used for filtration is graded silica sand but it is not 'designed' especially for pool filtration., while crushed glass and zeolite marketed for swimming pool filter use have been prepared specially for pool use and thoroughly scientifically tested. The test reports are usually by independent bodies but are of course used in the marketing arguments by the manufacturer/distributors those products.

DiamondKleen™ may now be difficult to obtain because the manufacturer, PoolRite, went into liquidation last year. Their assets have been bought by another company, Evolve, but I do not know about the current availability of DiamondKleen in Thailand. Contacting them at ... &Itemid=52 may enable you to find some links to suppliers here, or at least their importer. DiamondKleen™ used to retail in Thailand for around Baht 1,000 to Baht 1,200 per 15 Kg bag. It came in two grades, the coarse grade, No.20, and the fine grade No. 10.
There are other manufacturers/exporters of crushed glass for pool filters and I have seen them used here in Thailand. I can't remember who, but it may be Astral™ or Pentair™. You'll find out more about availability if you search Zelbrite , and DiamondKleen in Google iff youo add Thailand to your search words. Zelbrite is a lot less expensive than crushed glass and retails from around Baht 720 for a 15 Kg bag. These products last for many years longer than sand. Changing the media in a sand-type filter is a messy job and not one to be undertaken lightly. Some experts recommend changing the sand once every 3 years but i would say 5 is OK. I know of crushed glass and zeolite filters that are working at top performance after 9 years and still going strong.

Judging from the volume of your pool, a 1.5 HP pump would be about right. I am however slightly concerned about the 9 metre run from the pool to the pump house, and I can't remember if your pool uses a skimmer or an overflow system. The most important thing to take into consideration when buying a pump is the customer and product support. Brands such as Hayward™ (USA) and Emaux™ (Australia) are the most widely distributed here in Thailand and have excellent service backup in Thailand (although this may not always be provided by the actual retailer, and these are things you need to ask) and long guarantees. Astral is fairly common, but I think you will find that they are relatively expensive. I have heard reports that getting service may not be so easy in some areas. Kripsol™ KS 1.5 Hp certainly looks good but I have never come across them here in Thailand, so again, compare prices (€400 in Europe but expect to pay up to double here) and the availability of genuine service. From Hayward™ you could consider the Super II 1.5HP model or the TriStar 1.5 HP model, and from Emaux™ the SB15 model. Hayward™ is possibly the most well known brand in the world. The pump motors are made in Mexico by Smith Industries, and they are assembled to the pump part in the USA. Hayward products are very good and reliable but their price here may reflect the brand name and the shipping distances involved. Emaux pumps are reliable and designed in Australia and assembled in their own factory in China - but so are Apple computers. Spares and service are readily available.

220V vs. 380V 3-Ph: Even if you have a 3-phase supply, I would not necessarily recommend using it for your pump(s) for this pool. Generally 3-phase pumps start with 3 Hp models but some manufacturers offer smaller ones. They are obviously more expensive than single phase pumps and they require far more complex and expensive control panels (over-under line protectors, relays, wiring for the 220V timer, etc). A 220V pump can be run from a normal 220V outlet and through a timer. If you are opting for salt water chlorination (see:, you won't need a control panel for a 220V pump because the digital timers and pump protection are built in, if you use a simple Baht 400 relay you can run several pumps from the chlorinator control unit, but only one will need to have the chlorinator cell plumbed into the system. You will need to compare the cost of the initial outlay on your equipment with the expected cost of energy consumption, and consumption of chemicals and manually added chlorine. Electricity is cheap here in Thailand, so 380V vs 220V won't make a significant difference for your pool pumping for 6 - 8 hours per day. Remember that if you have a pool, all sorts of running and maintenance costs will be involved, so it's a bit like the old expression: If you can afford to buy a Mercedes, consider whether you will be able to afford the petrol and service costs. As a very rough guide, expect your electricity consumption for one 1.5 HP pump to be anywhere between baht 1,000 and 1,500 per month depending on what you are paying for a unit of electricity.

Filters are all pretty much the same and are generally offered in a variety of materials such as plastic, polycarbonates, fibre-glass, etc. Nothing much goes wrong with a filter tank, but some have better designs on the laterals (the bits inside that separate the sand from the water). Problems arise occasionally with the Multi Port Valves however. This is a complex piece of equipment and changing the spider gasket on the rotor is not everyone's cup of tea. On a price/performance basis, the Emaux™ V650 and the Hayward S244T are a good, all-round size and will match well with a 1.5 Hp pump and your pool volume. They should not cost more than about Baht 15,000 here in Thailand and some pools stores may even be cheaper. They both need 8 x 15 Kg bags of crushed glass or Zelbrite.

Whaterver the port sizes are on your chosen pumps and filters, always use 2" PVC pipe wherever possible (if your pump or filter has 1.5" ports, use a reducer (Baht 25). Always use 13.5 grade PVC pipe, never 8.5 grade. Keep the number of elbows (90° bends) down to a minimum as they reduce the flow significantly. Always use HD glue (and check that your installer uses it), never use the thin standard glue for PVC pipes, and allow the HD glue at least 12 hours to cure before putting the system under pressure.

Although some pools leak through the concrete walls, most leaks are found in improperly glued PVC piping, and that can be expensive if i's underground or difficult to access.

What you do and what you choose is of course up to you, but I do recommend doing a lot of web searching, because if you are based in Chiang Mai, you will probably end up knowing more about pools than your constructor , supplier, or installer. For locating suppliers here, it helps to add Thailand in the string as one of your Google search words. You will find huge differences in the prices offered for the same products. Some retailers don't publish their prices on their web sites - good luck when expecting a prompt ply to your emails ;) You might try dropping Kripsol a line and asking them directly who their distributor is for Thailand. If they have several, get quotes from them all. Check out the full description of the pump you have been offered at ... es---kse-4. In my opinion, it's likely to be disproportionately expensive and you need to e absolutely sure of service availability (whatever the vendor tells you).

I've just noticed from the photo that your pool is a skimmer type. Less efficient than overflow systems that most people are building now, but it will do the job although it may need some additional pumping time or a more powerful pump. It's not usually possible to adjust the draw between the skimmer and the main drain. Empirical experience will tell you.

I hope all this helps.
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