Choosing your swimming pool filter from SwimmingPoolsThailand

Contents (links)


Introduction

Calculating your filter
Filter media comparison
Sand filters
Cartridge filters

Diatomaceous earth (D.E.) filters

Swimming pools in Thailand should be filtered completely in about 6 to 8 hours total pumping time every 24 hours (Australian law), unless you are using a variable speed pump. Pumps and filters should be matched - a filter should preferably have a slightly higher flow rate than the pump. 

Swimming pool shop Thailand offers filters for all types of pools. Sand filters (sand, Zelbrite, and glass media), cartridge fiters, and diatomaceous earth (D.E.) filters. We also have replacement parts for all models we sell.  If you can't find what you're looking for, leave us a message or call us.

No two pools are alike, it’s impossible to publish a default working pressure or an exact flow rate and/or water velocity for your pool. We offer over 60 different models of sand filters, 14 cartridge filters, and the new range of Emaux D.E. filters. Every filter will settle at a different working pressure of its own depending on many factors such as:

• Pump power (HP)
• Pump head (Distance and height from the pool for suction)
• Distance from the pool for return, and number and type of return jets
• Pipe diameters
• Number of restrictions (ball valves, check valves, etc)
• Number of elbows in the piping

2. Calculating your filter: Simply multiply Length x Width x average depth, plus about 10% for your balance tank (surge tank) if your pool has an overflow or infinity edge design, then divide the result by 6 or 8 to obtain the required FLOW RATE per hour. Flow rates are displayed in the descriptions of all our filters. When designing your pump room layout, use as much space as possible to avoid using many elbows and bends which significantly reduce the flow rate and velocity.

3. Filter media performance comparison

• Zelbrite and D.E. are best but rely on different technologies. They can filter down to around 1 to 3 microns.
• Glass media: Sand filters filled with glass media typically filter pool water down to the 5 to 10 micron range, while premium specially activated glass can even capture particles as small as 3 microns
• Cartridge filter elements now come with down to 15 or even 12 microns and are the most user-friendly system.
• Sand has been used traditionally for filtering pools for over 100 years but it only filters down to about 30 to 20 microns.

4. SAND FILTERS: An economical, and hard-wearing type of swimming pool filter. The filters are economical to buy, fairly easy to install, but they need regular maintenance such as backwashing and rinsing, and because the sand builds channels and sticky clumps, especially in the Thai tropical climat the sand needs to be changed at least every three to four years. Sand cannot trap particles smaller than 20 microns on its own, it therefore relies heavily on pool chemicals (like clarifiers or flocculants) and chlorine to help clear up microscopic particles and bacteria. Replacing the sand with Zelbrite or glass media will significantly reduce the backwashing and its associated waste of water. The the filtration level is much higher -  resulting in noticeably clearer water, and these media will last for many years. BE SURE to use washed, graded silica sand - avoid beach sand or builders' sand.

When installing a filter, check that the laterals are firmly screwed into the centre pipe (they sometimes come loose during transport) and that the filter is half full of water before adding sand or or other filter media.

5. CARTRIDGE FILTERS have the smallest footprint of any kind of filter and are ideal for low bather load and installation in small spaces. The footprint is the same for all sizes.  They do not need backwashing. Emaux Cartridge Filters come with the elements pre-loaded, requiring very little time to set up. Easy Plug-and-Play, they occupy the smallest footprint , don't need so much plumbing, and they deliver excellent filtration down to 15 microns and without the inconvenience of backwashing or changing the sand or spider-gaskets.

Modern cartridge filters such as the Emaux Galaxy series of single and multiple element models offer high filtration levels with much less maintenance requirements compared with sand filters. Cleaned regularly, a cartridge may last for several years. Cartridges need to be removed occasionally for cleaning, thoroughly hosed down, and soaked in special cleaner for around 12 hours, after which they should be allow to dry completely before re-installation.

Our cartridge filter systems are delivered with one cartridge already installed. We recommend keeping a spare cartridge for use during cartridge cleaning to avoid down-time of the filtration system.

6. DIATOMACIOUS EARTH (D.E.) FILTERS are large, expensive, and maintenance intensive. They provide excellent filtration properties matched only by Zelbrite in sand fiters, but they are  messy and complicated to maintain. The filter is cleaned by backwashing after which new powder must be regularly added. The entire D.E. filter should be completely disassembled and thoroughly cleaned at least once a year and if the filter grids show signs of wear and tear, they must be replaced. We supply replacement grids for many brands and models of D.E. filters, please let us know what you need. We also supply D.E. powder at competitive prices. 

Spare parts: We stock all spare parts for all the Emaux filters we sell.

Call us on 042 109 710

Mon - Fri 09:00 - 17:00, Sat 09:00 - 12:00 except holidays

We  speak perfect English, French, German, and Swedish

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