Hot Tub Waterline Advice

Why ?

Waterline scum lines appear as a result of many different issues which can be summarised with an overall lack of user control of the maintenance of the hot tub.

Regular cleaning & balancing of the hot tub shell and spa water would reduce the chance of a build up to nil & keep the hot tub clean & clear.

Here below we explain how the scum lines appear and how to make sure your hot tub is stain free.


Ensure your chemicals dissolve properly into the water, as incorrect control will again result in a waterline of white.

This is the case in hard water areas where the chemicals take time to dissolve and also when using slow dissolving sanitisers such as Bromine.

A good tip is to pre-dissolve chemicals in a container of water and then apply to spa water after all is dissolved.



Maintain PH Levels

Managing your pool's water chemistry is a delicate balancing act.

The PH level range is recommended to be 7.2-7.6. 

High PH is a common cause of calcium and scale build-up which will show on the waterline whilst a low PH level will corrode metal parts and use allot of sanitiser which can lead to over dosing of the spa & then again lead to chemical staining.

To reduce this risk, balance the water on a regular basis and use PH plus or PH minus when appropriate.

Chemical Balance

Over dosing the hot tub with chemicals will lead to chemical staining of the waterline.

The fault lies with applying chemicals without first testing the water balance with testing strips

Keep your bromine / chlorine levels stable & correct to reduce the risk of staining

Shower Before Use

Before entering the hot tub, it is essential all users shower so all creams, oils, make up etc are removed.

Scum lines do appear on the waterline as the skin expels these partials back into the water which then build up around the water’s edge.

A shower will reduce the risk of this & with a weekly clean of the hot tub, the waterline should stay clean & free of scum.

Know Your Water

Water quality differs from area to area so a process which works in one City will differ from another.

Get to know your water and the understand there is a different procedure for hard or soft water.



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