How to prevent algae in a pool or hot tub

Warmer days and longer hours in summer provide the ideal opportunity to enjoy your pool or hot tub. As temperatures rise and UV rays become stronger, the effectiveness of the chemicals in your water is reduced - which may lead to discolouration and algae bloom affecting your pool water. We cover what causes algae in hot tubs and pools and how to prevent it below:

What causes algae in pool water?

Microorganisms, such as algae and bacteria, thrive in warm water. Hot tubs and pools that are heated by the sun throughout the day are in a temperature range that is ideal for growth, which is compounded by the reduced effectiveness of your water chemistry. Harmful bacteria feed on algae, which makes the pool or hot tub unsafe for use.

Chlorine is the primary sanitiser used for pools and hot tubs in the UK. Water evaporation, extended usage by bathers in hot weather and stronger UV rays break down the molecules of chlorine, leading to the water becoming unstable. Less sanitisation gives algae more of an opportunity to grow, with algae blooms appearing most commonly in the summer months in warm, stagnant bodies of water - including pools and hot tubs.

How to prevent algae bloom

Preventing algae from growing is easier than resolving this problem once it occurs. While algaecide can be utilised to treat algae once it appears, prevention is a more cost-effective way to keep your pool water sanitary. Some of the steps you can take to prevent algae bloom include:

Monitoring your pool water regularly

Measuring the water in your pool or hot tub is key to identifying any problems in water chemistry, allowing for a quick resolution. The HI-971044 Portable Photometer is an ideal solution for testing water chemistry at regular intervals, with the ability to measure chlorine, cyanuric acid and pH in one instrument. 

By testing the water at least once per day, you can quickly become aware of imbalances, allowing you to introduce more chemicals as required to prevent algae and bacterial growth. A portable photometer allows you to measure the water directly by the pool or hot tub, making the process as easy and efficient as possible.

Using cyanuric acid

Cyanuric acid, or CYA, is a stabiliser that helps to reduce the breakdown of chlorine under UV rays. Stabilised chlorine tablets for outdoor hot tubs and pools may already include cyanuric acid, or you can introduce it separately as required.

Cleaning your hot tub or pool

Ensuring your pool water is free of any organic material, such as leaves and plant matter, can help to keep the water chemistry in balance. Skimming, brushing and general cleaning all help to prevent build-up of debris. Hot weather leads to plant matter decaying faster, which uses up more sanitiser within the pool or hot tub, providing algae with the conditions required to bloom.

Buy pool testers and meters from Hanna Instruments

We stock a wide range of highly accurate hot tub testers, pool pH and multiparameter photometers in our Pool Line range. Shop our pool products online today.

Our pool experts are here to offer advice and guidance on the measurement of all key hot tub and pool parameters. Call us on 01525 850 855 or email us today to discuss your requirements.