# Filtering – Mechanical water treatment

Published on 07 April 2016

Category : Construct

An effective filtering system solves 80 % of water-related problems encountered in pools, the remaining 20 % are due to the chemical treatment.

### What is an effective filtering system?

The components of a pool filtering system are listed below in order of priority:

1. Sufficient number of suction - discharge sealing parts
2. An appropriate pump
3. A suitable filter
4. Suitable pipework

### How to determine whether the components are suitable filtration rate?

To make a choice compatible with the size of the pool:

The volume of a private pool must be filtered within 4 to 6 hours:

• 5 hours on average (4 hours in hot regions)
• Filtration rate = pool volume/recycling time

Flow rate Q = Pool volume/Recycling time = V m3 / 5 hours

### How to determine the volume of your pool?

Reminder: measuring units and calculation

#### Surface in m2

Length x width L x w = S m²

#### Volume in m3

Length x width x height*: L x w x h = V m3 *height = depth

π x Radius² x height: 3.14 x R² x h = V m3

#### Implemented slopes

Length x width x average height*: L x w x [(H1+H2)/2]

#### Pyramid trunk

Length x width x average height L x w x [(A+H)/2]

### How to calculate the required flow rate?

• The flow rate is expressed in m3/h
• This represents the quantity of water which passes through the facility within 1 hour

For example:

For a pool of 10 x 5 m with a depth of 1.50 m

1. Pool Volume:
• Surface: 10 x 5 = 50m²
• Volume: 50m² x 1.50 m = 75 m3
1. Filtration rate:
• 75 m3/5 hours = 15 m3/h

It is therefore necessary to choose equipment with a filtration rate of 15 m3/h

The 3 major standard components on the pool market

Pool < 4 x 8: 50 m3 = 10 m3/h

Pool < 5 x 10: 75 m3 = 15 m3/h

Pool < 6 x 12: 100 to 110 m3 = 22 m3/h

### What daily filtration time is to be used?

A pool must be filtered several times a day (not only during 5 hours)

The use is required to determine the filtration time:

Water T° / 2

Water at 24°C = filtration 12h per day – during day time (greater pollution)

For a pool of 10x5 with a depth of 1.5m, a filtration rate of 15m3/h is required to entirely filter the pool in 5h.

In summer at 24 degrees, the pool must be filtered during 12h, which means filtering the entire pool twice in a day.

In addition to the suction sealing parts and the pipework, which must allow the following volumes of water to pass through, two components are essential.

• The pump
• The filter
Pool EN