Blocking of the chlorine by overstabilization

What is chlorine blocking due to over stabilization?

Too much sunlight stabilizer

Over-stabilization is too much sunlight stabilizer, more than 70 grams per 1000L water (70ppm) 'UV stabilizer or Cyanic acid' in the pool water, this will block the effectiveness of chlorine. The chlorine in the pool water is therefore like NOT ACTIVE chlorine present.

This ensures that chlorine can no longer break down the dirt particles present, such as urine, sweat, bacteria and algae. As a result, there is no proper disinfection and the swimming pool water will no longer be pure and clear. Generally results this green or cloudy pool water.

Adding extra pool chlorine and still develop algae formation a typical phenomenon in over stabilized swimming pools.

TIP : Prevent green water by using HTH Chlorine.

The stabilizer (cyanuric acid) used in the classic chlorine products protects the chlorine against degradation by sunlight (effect of UV rays). However, it uncontrolled addition of stabilizer to these chlorine types ensures that the disinfecting effect is blocked.

As a result, the chlorine present is no longer ACTIVE and the water becomes cloudy or green.

The annoying thing is that the more you add this chlorine, eg as chlorine granules for a shock, the more you also add sunlight stabilizer. Ultimately, this leads to an OVERstabilisation.

How much stabilizer do you add with stabilized chlorine?

Evolution cyanuric acid stabilizer during the season

The amount of stabilizer builds up

Swimming pool season, after swimming pool season the amount of stabilizer in the swimming pool water builds up. Each time you add the 200g chlorine tablets or the chlorine granules you are in fact adding more sunlight stabiliser.

This stabilizer is useful to prevent too rapid degradation of chlorine by sunlight. The stabilizer remains in the water. The chlorine reacts with the dirt and disappears every time it breaks down dirt particles, bacteria and algae.

The amount of cyanuric acid stabilizer decreases during the low season. Then you do not add chlorine (so no stabilizer) and it will backwash and the rain dilute the pool water.

Blockage of the chlorine due to overstabilization can therefore only occur after a number of seasons.

It can therefore be perfect that you the first 2 to 3 swimming seasons no problem of the blocking effect of the stabilizer but, for example, with the 4 the summer season suddenly problems with green and cloudy swimming pool water.

How do I prevent green or cloudy swimming pool water due to overstabilisation?

Prevent green water with HTH Chlorine

Prevent green and cloudy swimming pool water by using HTH Chlorine. So it is a simple solution for this use of NOT stabilized chlorine from it brand HTH. This is inorganic chlorine based on calcium hypochlorite. This chlorine type always has ACTIVE available chlorine that has a better disinfecting effect and acts directly on algae, bacteria and dirt particles such as sweat and urine.

Swimming pools properly treated with HTH Chlorine granulate or HTH chlorine sticks will prevent the blocking of the chlorine and are therefore not green during the summer.

READING TIP : Chlorine tablets – find out everything, tips, composition and use.

How can I lower the cyanuric acid stabilizer in my pool?

You reduce the amount of cyanuric acid sunlight stabilizer by ; It diluting the pool water, with carbon filters or UV treatment.

The first and simplest method is to remove water from the pool by backwashing or pumping it out. Then add fresh water. In private swimming pools, the costs for this are low and also feasible. In public swimming pools, due to the high costs for heating, the water itself and the cost of the products, this is not a sustainable method.

Therefore, the 2nd method most commonly used in public swimming pools is multi-layered filters filter material with activated carbon on top. The multi-layer filtration happened with molars at the bottom, different types of sand in the middle and an activated carbon layer on top.

The last method is also regular UV disinfection used. UV rays break down all dirt particles and bacteria. In addition, this treatment does not add chlorine or chloramines to the pool water.

What is the chlorine stabilizer for?

Cyanuric acid stabilizer may also be helpful

It is especially useful in sunny southern countries where there is a lot of sun and therefore UV sunlight protect chlorine from degradation by this sun with cyanuric acid. Therefore be stabilized chlorine tablets useful too.

In the more Northern countries such as Belgium and the Netherlands, this function is less useful.

Blocking of the chlorine due to over stabilization (too much cyanuric acid) is therefore common in southern warmer countries, but unfortunately also more and more in Belgium and the Netherlands due to the warming of the climate.

What are the consequences of blocking the chlorine due to overstabilisation?

The consequences of overstabilisation, a too high concentration of cyanuric acid greater than 70 grams per 1000L water (70ppm), are cloudy and green swimming pool water.

The typical phenomenon is that your water is cloudy, you add chlorine, measure enough chlorine but it does not get dissolved. This is due to the blocked chlorine which cannot kill the dirt particles, algae and bacteria.

The solution is it adding ACTIVE available chlorine. First dilute, then a chlorine shock with HTH Chlorine and then using a flocculant such as, for example Flovil super flocculation.

How much stabilizer should I use in my pool?

The relationship between stabilizer and bacteria

The ideal concentration of cyanuric acid stabilizer

The ideal amount of cyanuric acid stabilizer in pool water is 25 to 50 grams per 1000L of water (25 to 50ppm).

When the concentration is higher than 70 grams per 1000L of water (70ppm), the pool water is overstabilised.

You can measure the concentration of cyanuric acid with the Aquacheck 4 in 1 test strips and the 6 in 1 Test Strips.

Relevant blogs about chlorine blocking by stabilizer

Reduce cyanuric acid in swimming pool water