Frequently Asked Questions

Here you will find answers to frequently asked questions.

Swimming pools

What should I do to maintain the water in my swimming pool?

Sadly, the tap water that you used to fill your swimming pool will not remain as clear and as healthy as it was at the beginning. If you don’t treat the water, it will quickly become dirty and/or green and may become a harbour for germs. Interline water treatment products are a good way to keep the water in your swimming pool in good condition. You don’t need to put in a lot of effort to achieve an attractive result – water that sparkles so much that you can’t resist jumping straight in. To maintain nice, clear and healthy swimming pool water, we’ve developed a special STEP-BY-STEP PLAN to help you. This gives you a quick overview so that you can keep your water in good condition. 
​​​​​​​You can see the step-by-step plan for clean bathing water here!

What should I do if there are insects/worms floating on my swimming pool?

Swimming pool chlorine is designed to disinfect bathing water and is effective against bacteria and algae. You can remove pests with a net.

How do I add chlorine to my swimming pool?

At normal dosage, chlorine tablets should always be put in a chlorine floater or skimmer. Chlorine granules (powder form) should always be dissolved in a bucket of lukewarm/warm water before you distribute the chlorine mixture over the surface of the water. You can now use the swimming pool, but you should always ensure that chlorine tablets/floaters or granules remain out of the reach of children! We recommend that you do not add chlorine before swimming and that you remove the chlorine floater from the water when you are swimming. Keep chlorine out of the reach of children. Always read the instructions for use on the packaging.

How should I give shock treatment?

Start by checking the pH level and adjust it to the optimal level, if necessary. Then add the chlorine granules. Click here for the dosage schedule to ensure that you have the right amount. You should always dissolve the chlorine granules in a bucket of lukewarm/warm water first. Never dissolve more than 300 grammes of granules per bucket. If you need to use a larger quantity, distribute it amongst several buckets. You should then distribute it over the surface of the water (immediately). Leave the pump/filter running continuously for 24-72 hours.

How many chlorine tablets or granules should I add to my swimming pool to ensure the correct dosage?

This depends on the water content (and temperature) of your pool. Chlorine tablets are used primarily for continuous dosing, while granules are used mostly as a rapid solution (shock treatment). Click here for the dosage schedule overview. Always dose chlorine and pH agents separately!

I have just put a large quantity of chlorine in my pool, can I swim now?

No, you should wait for at least six hours before going in the water. We recommend adding the chlorine in the evening, after swimming.

Can I swim in green water?

Yes, it’s okay to swim in green water, but we recommend treating it with shock treatment first. Click here for the dosage schedule to ensure that you have the right amount.

My water has turned green (also after a storm), what should I do?

Start by checking the pH level, then adjust, if necessary (wait for one to two hours after heavy thunder showers). Then measure the chlorine level and adjust, if necessary (e.g. with shock treatment). Click here for the dosage schedule to ensure that you have the right amount.

Can I fill my swimming pool with groundwater?

No. The iron in the groundwater will turn your swimming pool water darker.

My water is milky white in colour, what should I do to rectify it?

This is often caused by an incorrect pH level. You should start by measuring the pH level, then adjust it with pH Minus or pH Plus. Filter frequently and clean the filter cartridge at regular intervals. If you have a sand filter, it should be backwashed regularly (e.g. every two hours).

Why should I measure the pH level?

The recommended pH level of the water should be between 7.2 and 7.6 so that the disinfectant (chlorine) can work properly. You can measure the pH level with test strips. Always keep pH correctors out of the reach of children!

What should I do if my pH level is incorrect?

Correct a high pH level with pH Minus and a low pH level with pH Plus. You should always dissolve the pH corrector in a bucket of lukewarm/warm water first. Then distribute it over the surface of the water. Run the pump/filter. You can test again after around two hours and adjust, if necessary. You can now swim as normal. Click here for the dosage schedule for pH Minus and here for the dosage schedule for pH Plus.

How do I connect my Simply Genius water maintenance system?
What’s the best way to drain the water from my swimming pool?

Chlorine is harmful to the roots of grass and plants and can kill beneficial soil fauna (single-celled organisms and fungi) that helps to maintain the condition of your plants. It’s also illegal, under the Domestic Waste Water Decree, to allow water containing chlorine to run into the garden. This water is considered to be ‘polluted’ and harmful to the environment. You could receive a large fine if you do! The best thing to do with swimming pool water containing chlorine and pH agents is to drain it into the sewer. Use a garden hose, swimming pool hose or submersible pump to drain the water. Route the hose to the sewer opening, a drain in your garden or even to a toilet or shower. If your home is connected to a separate sewer system, you should drain the water via the domestic sewer.

What’s the best way to clean the filter balls of the Interline Fiberclean cartridge?

The filter balls can be washed in the washing machine on the handwash cycle (note: max 30°C, without soap or detergent). 

Is chlorine harmful to my (artificial) grass?

Artificial grass around your swimming pool is an ideal solution. Chlorine cannot cause discolouration or damage, unlike with real grass. Chlorine is extremely harmful to real grass and plants.

Can Simply Genius be combined with chlorine tablets?

Simply Genius has been developed precisely so that, under normal conditions, you no longer need any other products to treat the water in your swimming pool. We discourage interchanging products. Is it an exceptional situation? If it is, you can contact us so that we can advise you on the best course of action.

How long can you store chlorine/anti-algae agent?

Liquid chlorine has a short shelf life of around three months.
Powdered chlorine has a shelf life of five years after the packing date; after five years, its effectiveness will be less, but will not be harmful. Chlorine packaging will always bear an expiry date. Ensure that you keep your chlorine in a cool and dry place and out of the reach of children.
Anti-algae agent has a shelf life of one year. After a year, the effectiveness of the anti-algae agent will be less, but not harmful.

Where’s the best place to store my chlorine floater?

You should store the chlorine floater in a cool and dry place.

For how long should you refrain from swimming after a chlorine shock?

It depends on the reason for using the chlorine shock. If it’s to move the chlorine level to between 1 and 3 ppm, you should wait for around one hour. If it’s to raise the chlorine level to 10 ppm (such as to kill algae), we recommend staying out of the pool for at least twelve hours.

How frequently should I test the pH and chlorine levels of my swimming pool?

We recommend testing the pH and chlorine levels once a week.

Saunas/infrared cabins

What’s the difference between a traditional sauna and an infrared cabin?

There are a number of significant differences between a traditional sauna and an infrared cabin. The following is an overview:
A traditional sauna is heated by a stove, which means that temperatures can rise to as high as 90 or 100 degrees Celsius. An infrared cabin is heated by infrared emitters, which means that the temperature generally rises to between 45 and 65 degrees Celsius. Quite a difference.

Traditional saunas are usually much larger than infrared cabins. Our cabins are available in a minimum size of 100 x 94 x 190, while our saunas start at 208 x 200 x 205.

Method of use
The experience you will have in a traditional sauna and an infrared cabin will differ, partly because of the temperature. A session in a traditional sauna generally lasts for around fifteen to 20 minutes, after which a cold or ice cold shower is recommended. A session in an infrared cabin is usually around 30 to 45 minutes, after which a lukewarm to warm shower is sufficient.

Please note: You know your own body best and if you feel uncomfortable, you should leave the sauna/infrared cabin.

Can you go into the sauna when pregnant?

Opinions here are divided. Some scientists recommend not taking the risk, while others believe that there is no harm in it, so long as there have been no complications during your pregnancy and you are used to the sauna.

We do not recommend using a sauna during the first trimester of your pregnancy. This is because your baby is still developing and your body is additionally vulnerable.
In the final six weeks of your pregnancy, the use of herbs is discouraged due to the possibility of dilation.

Should you cool down after using a sauna?

Yes, you should always cool down after using a sauna. The heat of the sauna will cause your body temperature to rise and if you don’t cool down after a sauna session, you will continue to sweat and are at risk of headaches and/or shortness of breath. The way in which you cool down is up to you – going outside, taking a cold shower or perhaps even a plunge pool!

Is infrared dangerous?

It is perfectly safe to use your infrared cabin on a regular basis. There are no restrictions and you can use it as often as you want to. A session of 20 to 30 minutes is commonplace. You should always pay attention to your body, of course, and if you are uncomfortable in the heat, it is best to continue the session at another time.

What types of infrared emitter are used in the Interline infrared cabin?

Long-wave infrared emitters – these are best able to penetrate the skin and raise your body temperature, causing you to sweat. The rays have an invigorating and relaxing effect, and a beneficial effect afterwards.

What is infrared radiation?

Infrared radiation is a component of light. It is around us all the time, we just can’t see it. We can feel it though, primarily as warmth. As an example, the warm feeling of sunlight on your skin is caused by infrared. The emitters in an infrared sauna give your skin that same warm sensation.

How does infrared work?

Infrared radiation penetrates the top layer of skin without warming it. Deep heat is then generated and absorbed by the body. This helps to boost blood circulation, particularly in the skin. Blood vessels in the underlying fatty tissue absorb the deep heat, widen and thereby improve the flow of blood through the tissue. The fatty acids stored in the fat cells are dissolved and are removed from the body via the lymphatic system. The overall effect is the removal of all waste products from the body. It is also raises the heart rate slightly, in effect giving you a passive fitness training session. A visit to a sauna is a good way to cool down after exercise and helps to prevent muscle pain.

What type of wood is the Interline infrared cabin made of?

The Interline infrared cabin is made of durable hemlock wood, a strong, robust wood with a fine structure.

Do I need an additional power supply for an infrared cabin?

No, an Interline infrared cabin can be connected to a standard 220 V socket.


What is the difference between a spa, a jacuzzi and a whirlpool?

There no difference in meaning between these terms. What most people don’t realise is that ‘Jacuzzi’ is a brand name and not a product type like a spa, which means that companies cannot simply use the name. Whirlpool is the English name for a spa, and is increasingly used elsewhere. Ultimately, they all mean the same.

What type of connection do I need for my spa?

This varies between models, so you should check the specifications on our website carefully, or ask our specialists.

What is the correct pH level for my spa?

The correct pH level for your spa is between 7.2 and 7.6. To test this, you can use our pH test strips. Can’t quite work it out? Then please get in touch with us.

How frequently should I change the water in my spa?

We recommend doing this around every three months. It’s very important that you maintain the spa properly in the meantime. Please note that this is merely a guideline and you may find that the water needs to be changed more frequently. There could be a number of reasons for this, including how intensively you use the spa, interim maintenance, the size of the spa, not rinsing before getting in, etc.

Should the spa be drained in winter?

A spa is designed to be used in all seasons, so the water does not need to be drained. If you don’t plan to use the spa for a while, we recommend draining the water.​​​​​​​

What is the power consumption of a spa when it is outdoors?

This can be calculated as follows:

(litre capacity of spa x 0.00116 kW* x 3.5 degrees** = kWh)
* kW required to increase the temperature of 1 litre of water by 1 degree
**Heat loss in degrees, for a 2 kW boiler, per day.
Gives the following: 681 x 0.00116 x 3.5 = 2.77 kWh per day

Circulation pump:
2 hours per day (2 x 400 W)
Gives: 800 x 0.00116 = 0.93 kWh per day

Jet pump
2 hours per day (2 x 500 W)
Gives the following: 1000 x 0.00116 = 1.16 kWh per day

Total: Standby costs of spa = 2.29 kWh x €0.23 = €0.64 per day
Running costs of spa = 2.09 kWh x €0.23 = €0.481 per week = €0.481 : 7 = €0.07 per day

Total cost of spa: approx. €0.71 per day (€0.64 + €0.07)

(This depends, of course, on usage and electricity prices, in the example €0.23 and without guarantee).