Flocculation: What is it?

This is due to the presence of small suspended particles. The use of a flocculating agent is therefore essential to restore crystal-clear water.

Why flocculate?

Pollutants in swimming pool water can be classified according to their particle size or consistency. The larger the particle, the easier it will be to filter. However, small particles can still pass through the filter. Thus, a filter with a low filtration fineness will filter small particles. Sand filters have a filtration fineness of 20 to 50 µm. Thus, particles smaller than 20 µm will not be retained by this type of filter. These particles are almost always organic matter, and when they are not trapped by the filter, they can slow down the disinfection process. It is therefore necessary to increase their size in order to trap them in the filter: this is done through flocculation. Flocculants destabilize the electrical charges of small particles and allow them to come together. By clumping together, their size increases so that they can be retained in the filter.

This effectively eliminates and removes metal ions, colloidal pollutants, and microorganisms from the pool water. This results in clear, more crystalline water, making it easier to clean and saving on disinfectant.

Please note: It's important to know that some types of microorganisms are even resistant to disinfectants. The only way to get rid of them is to combine flocculation and filtration. For these reasons, a flocculant should be used in public pools using sand filters.

Settings	Recommended values
pH	7.0 – 7.4
Calcium hardness (TH)	> 50 mg/l CaCO 3
Alkalinity (TAC)	> 80 mg/l CaCO 3

Recommended parameter values ​​using flocculant

Manual use

To promote better filtration, we have created a sock flocculant called ACTI FLOC BAG . Placed in the skimmers or in the pump pre-filter, ACTI FLOC BAG Gradually releases its flocculating agents and helps improve filtration while clarifying pool water. Furthermore, as its action is gradual, it prevents the formation of suspended particles and eliminates those already present. It is therefore the ideal product for all sand filters.

Instructions for use

Allow one sock for ^every 30m3 in the pump pre-filter or in the skimmer after backwashing the filter. First, check that the pH is between 7.0 and 7.4. Renew every 10 to 15 days.

Note : flocculation can also be done punctually using liquid flocculating product ACTI FLOC . Simply set the pH between 7.0 and 7.4 and pour 0.20l / 10m ³ water to be treated directly in the pool skimmer.

Automated use (recommended in public swimming pools)

Given the large volumes of pools and filter elements, it is recommended to use an automated installation to ensure optimum comfort for all bathers. This type of system effectively combats the significant influx of particles from bathers. With this in mind, we have developed the product ACTI FLOC , a concentrated product specially designed for community use. Thanks to its high concentration, ACTI FLOC ensures crystal clear water at all times. Its packaging (in 1, 5 or 20L containers) provides significant autonomy, thus avoiding any repeated handling. It is therefore the ideal product for all public swimming pools using sand filters.

Instructions for use

The flocculant is injected continuously by a dosing pump, after the pump's pre-filter and before the sand filter, directly from the container. The continuous injection varies depending on the pool's usage and environment.

Basin in compliance	100 m3	400 m3	2500 m3
Recycling per day	1400 m3 /day	4000 m3 /day	20,000 m3 /day
Indoor swimming pool	1 l/day	3 l/day	7 l/day
Outdoor swimming pool	2 l/day	5 l/day	12 l/day

Quantity of pure liquid flocculant used per day in routine application.

Note 1: The flocculant injection point should be placed after the pump prefilter and before the sand filter. Due to the speed of the flocculation process, it is necessary to ensure that the mixing between the flocculant and water at the injection point is sufficient. This can be improved by increasing the diameter of the pipe at the injection point.

Note 2: Flocculation should be applied according to:

• the filtration speed
• the height of the filter layer

Cleaning the filter

Despite excellent flocculation, your pool water may remain cloudy. This may be due to your sand filter. It's therefore important to maintain your filter carefully. To ensure optimal operation:

• Carry out a backwash once every 10 to 15 days (depending on the internal pressure of the filter, position the 6-way valve “WASH” for approximately 2 minutes. Then, position the 6-way valve on “RINSE” for 30 seconds.
• Carry out regular, thorough cleaning/descaling when opening the pool and at the end of the season. If the water is very hard (TH> 35°f), carry out this operation once every 6 weeks.

For this we recommend the product ACTI CLEAN FILTER ; a filter cleaner whose formulation is specially designed for all filter elements.

For sand filters: destruction of scale deposits, rust and, in general, all deposits of mineral origin present in the filter media.

Instructions for use:

• 1 liter for 75kg of sand for family swimming pools (“fast” filtration)
• 1 liter per 100kg of sand for collective swimming pools (“slow” filtration)
• Backwash the filter then rinse.
• Introduce the product upstream of the filter (skimmer, chute or pre-filter) start the filtration for a few seconds in the “Drain Rinse” position to disperse the product in the filter until the color appears in the control indicator.
• Leave to act for at least half a day, or even overnight.
• Backwash and rinse the filter thoroughly until the discoloration has completely disappeared.

Note : Although more restrictive, the best method is to pour the product directly into the open filter, onto the sand, after taking the precaution of bringing the water level to the level of the sand and closing all the valves.

Why change the filter sand?

Filter sand inevitably wears out. When new, the sand has grains with a well-defined size and outline. During use and with each backwash, the grains become polished by the water circulation and become increasingly smaller. It is therefore imperative to change the filter media approximately every 5 years.