Get great tips for starting up your pool after winter. Learn about preparation, filling with fresh water, water balance, safety, and everything else that ensures a great pool season.

When the days get brighter and the sun starts warming up the garden, it's time to bring your pool back to life after winter. A well-executed startup not only ensures clean and crystal-clear water but also a trouble-free pool season without unnecessary surprises.

In this guide, you will receive step-by-step instructions on how to start up your pool after winter closure and recommendations for products that can make the process easier and more efficient.


The Best Time to Start Up Your Pool

The optimal time to start up your pool depends on the weather and temperature. Generally, it is recommended to begin when outdoor temperatures consistently exceed 10-15 degrees Celsius, which in Denmark is typically from mid-April. This is when the sun's warmth starts influencing the water, and the risk of night frost is minimal.

Many prefer pool water to be at least 20-22 degrees Celsius. A good heat pump can help reach this temperature quickly and efficiently, even during the cooler periods at the beginning and end of the pool season.

If you are considering using your pool during winter, it is possible to keep it running year-round. However, this requires a good pool cover, a powerful heat pump that can withstand sub-zero temperatures, and regular water circulation. Additionally, it is recommended to supplement with a thermostat-controlled electric water heater, which provides extra heat regardless of air temperature. Alternatively, the pool can be used for cold water plunges.


Step 1: Preparation Before Cleaning the Pool

Before you start cleaning the pool, it’s a good idea to have all the necessary equipment ready. Nothing is more frustrating than having to interrupt the process because something is missing. Proper preparation speeds up the cleaning process and ensures optimal results.

Checklist of Essential Items:

  • Starter Kit – Contains essential water care products for pool maintenance.

    • The chlorine kit includes: pH Minus, pH Plus, Chlorine Starter, KlarPool, and test strips.

    • The chlorine-free kit includes: pH Minus, pH Plus, OxyChock, Activator, and test strips.

    • If you have leftover products from the last season, you can supplement as needed.

  • Pool Cleaner – Effective for removing lime deposits and rust that may have accumulated over time.

  • Telescopic Pole – Used with a pool brush and skimmer net for thorough cleaning.

  • Pool Brush – Helps remove deposits from pool surfaces without damaging the liner.

  • Cleaning Sponge or Hand Brush – Perfect for cleaning along the waterline where dirt often accumulates.

  • Bottom and Surface Net – Removes leaves and debris from the pool bottom and surface.

  • Pool Vacuum or Pool Robot – A pool vacuum removes small particles, while a pool robot does the work automatically.

  • FilterBalls, Filter Sand, or Filter Glass – Check if your filter medium needs replacement for optimal filtration.

  • Teflon Tape – Ensures tight connections in the pool’s piping system.

  • Summer Cover/Thermal Cover – Retains heat and protects water from debris.

  • Skimmer Net – Efficiently collects leaves, pollen, and other dirt before it reaches the filtration system.

By having the right equipment ready from the start, you ensure a more efficient cleaning process and can quickly move on to the next step.


Step 2: Preparing the Pool and Pool Equipment

Before adding more water to the pool and starting the filtration system, it is important to check the equipment to ensure everything is functioning properly. Minor issues can easily be fixed now, saving you trouble later.

The Pool:

  • Remove the winter cover – Hopefully, you used a winter cover to prevent dirt from accumulating in the water. Clean and store it for next time.

  • Remove winter accessories – If you used a winter kit, pack away the winter pillow and floats, remove the winter plug, and install the skimmer return nozzle.

Filtration System:

  • Check all connections and replace any worn rubber rings.

  • Ensure connections are sealed with Teflon tape and replace if necessary.

  • Fill the filter tank with the necessary filter medium (FilterBalls, filter sand, or filter glass).

  • Consider whether it is time to replace the filter medium for better filtration.

Heat Pump:

If you have a heat pump, you can start the pool season earlier. Remove the cover from the heat pump and clean the fins if they are dirty. Remember to turn off the power before cleaning!

Connecting Pipes and Hoses:

  • Check all connections and tighten hose clamps where necessary.

  • If using a bypass system, ensure it is open in the correct places.

Once the pool and equipment have been inspected, connected, and prepared, you can move on to cleaning.


Step 3: Cleaning the Pool

Before adjusting the water quality, the pool must be thoroughly cleaned.

  • Remove lime and rust – During winter, some water evaporation is inevitable, leading to lime deposits along the pool edge. Use Pool Cleaner and a sponge or brush to remove deposits.

  • Use a pool net – Remove leaves and dirt from the bottom and surface.

  • Brush sides and bottom – Over winter, deposits can form on the pool walls and floor. A pool brush easily removes these.

A pool robot can be a big help with heavy cleaning and save time for the rest of the season.
 

Step 4: Filling the Pool

Fill the pool with fresh water up to halfway over the skimmer, turn on the filtration system, and check for leaks.
 

Step 5: Crystal Clear Pool Water with Water Treatment

Now for the most satisfying step – making the pool water inviting and crystal clear. The right water care products not only keep the pool looking great but also ensure healthy swimming water.

How to Make Pool Water Clear and Inviting:

  1. Turn on the filtration system – Ensure proper circulation before adding chemicals.

  2. Test the pH value – Use a test strip to measure the pH. The optimal range is 7.0-7.4.

  3. Adjust the pH value:

    • If pH is above 7.4, add pH Minus.

    • If pH is below 7.0, add pH Plus.

  4. Sanitize the water:

    • Using chlorine:

      • Start with a shock treatment using Chlorine Starter.

      • Add KlarPool to prevent deposits.

    • Using chlorine-free treatment:

      • Start with a shock treatment using OxyChock.

      • Add Activator to extend the effect.

After at least an hour of circulation, check the chlorine or oxygen levels to ensure they are within the correct range.

Enjoy Your Pool!

Once the water has circulated for at least an hour, and you have checked that the chlorine or oxygen levels are correct, you are ready to jump into your crystal-clear and clean pool!
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