By HOT TUB SERVICES LTD – A water treatment company with over 13 years experience operating in the Lake District, Cumbria .


The reason for HTS asking its’ clients to jointly finance an extensive program of laboratory tests is to provide, and have on record, convincing evidence of the safe and robust water treatment of Holiday Let Hot Tubs provided by my Company, which we feel is essential both to protect HTS but also our clients interests .

Since the introduction of the new HSG282 Guidance Document in 2017, which is a very comprehensive document of 62 pages, we have seen widely differing views on how it should be implemented.

The key document in the implementation of HSG282, in my view, is the letter HTS obtained from HSG282 Directorate dated 2nd February 2017 , who issued this document (we enclose a copy for your information at the end of this report).


There appears to be two main views:

a) HTS who apply a “Proportionate Risk – Based Approach towards Health & Safety” as preferred by HSG282 Directorate.


b) Several major holiday park companies, major holiday let groups and other concerns involved in hot tubs, who have first decided HSG282 is mandatory (which from the HSG282 document and HSG282s’ letter it clearly is not) and to comply with it by choosing a limited number of tasks, typically;

– Changing water after each guest
– Twice daily visits 7 days per week
– Monthly Laboratory tests


MASSIVE INCREASE IN COSTS FOR HOLIDAY LET TUB OWNERS directly due to substantial increase in number of water changes and significant increase in labour to visit twice daily and high number of laboratory tests. Potential clients have reported to HTS being quoted monthly prices of £480 per month inc VAT (compared to HTS at approx. £240 excl VAT); and this does not allow for the significant increase in cost of water and electricity to reheat tubs for the owner.

ENVIRONMENTAL AGENCY, concerned at substantial increase in water consumption and disposal of water with high chlorine content into sewer systems has started to impose limitations on how many hot tubs can be allowed in certain holiday parks.

HTS condemns this b) approach, which apart from being 180 degrees away from HSG282s’ stated “ethos” of a proportionate risk-based approach, is a blunt robotic approach justified falsely in that it is necessary to comply (legally) with HSG282 and often enforced on vulnerable holiday let owners. Of course it is easy for concerns to do this, when it is not them but the owners of the tubs who are paying the inflated prices demanded.



2.1 TWICE DAILY VISITS – HTS has 10 years of records of visits to hot tubs and their safety and chemical condition (over 40,000 individual records). In the last 2 years our technicians have switched from paper records to digital recording on tablets, so that we can instantly retrieve records on any tub from our Cloud Storage. We took several months of records earlier in 2019 and compared the chemical levels of pH and chlorine on a Friday with the levels found on the following Monday. We found in 98% of cases the tubs had a safe level of chemicals on the Monday. Had HTS or anyone visited these tubs twice daily over the weekend they too would have found similar safe results i.e. in our risk assessment the value of twice daily visits would be given a very low priority.

HTS took at random, about 20 tubs which had water change frequencies from 3 days up to 23 days and sent samples for laboratory tests for E-coli. They all passed. HTS wished to determine if there was any obvious connection between extended water change(w/c) frequencies and failures in bacteria tests (as opposed to changes after each guest, which would in most cases be 3 days).

Both the above Twice Daily Visits and Water Change investigations were presented at a meeting with senior members of Health & Safety Executive, one such person working solely in Legionella & also in the presence of a senior director of BISHTA (British & Irish Spa and Hot Tub Association). Contrary to expecting some interest in these investigations HTS was requested to back up our results with further independently supervised laboratory tests, which have now been completed in the case study written below.

At this meeting BISHTA referring to w/c frequency, was adamant that the formula mentioned in HSG282 for calculating w/c frequency did not apply to Holiday Let Tubs, but only to the Commercial spa –pools with sand filters in 282. BISHTA went on to state, that as far as they were concerned no formula existed for calculating w/c frequency for holiday let tubs.
HTS forwarded to BISHTA after this meeting a copy of Lovibonds’ Pool & Spa Water treatment and Analysis Booklet (which I strongly recommend to any one interested in this subject, available from Tintometer Ltd Uk Tel 01980-664800) which on Page 31 gives full details of a long standing UK formula for calculating the water change frequency of any spa; in the Foreword acknowledgement is given to contributors including Mr Howard Gosling, who is BISHTAs’ senior technical advisor on water treatment.

BISHTA then conceded, that w/c after each guest was merely a “Preference” i.e. a wish to have a tub unused by previous guests and of no relevance to safety, which is the prime concern of HSG282. Additionally unused water is unheard of anywhere else in the water leisure industry; swimming pools only have their water changed gradually over one year. There should be no place in HSG282 for a preference – this is merely someone (at BISHTA?) trying to spend tub owners’ money; if owners want to offer tubs with unused water they are free to do so and charge or not as they wish.

Example of using Lovibond formula:
Formula: A 500 gallon spa (2.37m³) needs changing after 250 bather load hours.
A typical tub serviced by HTS has a capacity of 1.12m³ which would therefore need changing after (1.12 divided by 2.37 x 250) = 118 bathers. So if bather load is expected to be 4 persons using tub twice per day for 1 hour (4 x 2 x 1) 8hr per day bather load divided into 118 equals 14.8 days between water changes.



3.1 Independent Supervision by AQUA ENGINEERING SOLUTIONS Limited a very well respected company with over 20 years experience in the water treatment and laboratory testing of swimming pools and hot tubs and other equipment including legionella bacteria prevention and treatment .

3.2 AQUA were asked to visit a total of 100 hot tubs and record their pH and chlorine levels and to take samples for laboratory testing: these tubs had had their last water change from 3 to 21 days and were last treated by HTS on the Friday before Aqua tested them on the following Monday (and before HTS treated them on the Monday).

Tests were broken down into 4 visits /testing 25 tubs approx., at a time. Tests were made for Legionella, E.Coli/Coliform and Pseudomonas .

3.3 Test pass results :

Legionella: JUNE/JULY/ AUG/SEPT of 100%
E.Coli/Coliform and Pseudomonas: JUNE/JULY/ AUG/ of 86% & SEPT of 96%

3.4 Analysis of pH and chlorine levels
pH levels were typically in the 7.00 to 7.60 range recommended in HSG282. Chlorine also in recommended range and confirms Twice Daily visit would show same acceptable results making 2 x visit worthless. Chlorine was nearer 3 mg/l rather than 5 mg/l of the recommended range 3-5 mg/l during June – Aug period.

Therefore for the Sept test HTS, on the Friday before lab samples were taken on the Monday, deliberately increased the dose of di-chlorine granules to ensure and achieve a chlorine level of 5mg/l. Pass Result levels in 4th batch test, then rose to 96%!

3.5. AQUA were asked for their views on the results .
David Bradshaw, M.D. said compared to results Aqua typically get from tubs they test at hotels & holiday parks etc, these results with HTS clients’ tubs were “exceptionally good” in his view. He also complimented HTS in being prepared to experiment by increasing chlorine to 5mg/l for 4th test run to see what effect that would have – and what a positive effect increasing pass rate from next highest of 86% to 96%!

He concurred with HTSs’ view , that in the holiday let tub application, which can be intense usage for a Domestic designed tub, one should aim for chlorine level to be at or as near as possible to the upper 5 mg/l recommended chlorine level.

HTS will adjust its’ procedures accordingly and target to work, in future, nearer the higher 5mg/l chlorine level due to its’ beneficial effect on reducing bacteria (compared to the lower 3mg/l): the higher chlorine level appears to be necessary with this application.



1. Water Change Frequency recommendation should be changed to “as per risk assessment using Lovibond Formula” (Not after each guest).

2. HSE should consider including the Lovibond w/c frequency formula in the HSG282 guidance document as an aid to entrants in water treatment.

3. Twice daily testing should be changed to “as per risk assessment”.

4. Laboratory Tests – changed to “monthly, or as per risk assessment”

5. Page 45 Under Disinfectant 3-5 mg/l …instead of Recommended Action “None” to be changed to “ 5mg/l for holiday let tubs”

Technical report written by,

Peter J. Harman
Technical Director,
on behalf of Hot Tub Services limited