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Cooling Water Dipslides

Cooling Water / HVAC Dipslides (Box of 10)

It is important to test the 'general health' of cooling water. You can do this using our CWBTM2 (Nutrient and Malt Extract Agar) dipslides. Ideal for cooling towers and HVAC testing.


By buying this product you can collect up to 11 points


CWBTM2 Volume discounts

Quantity Price You Save
51 £11.33 Up to £32.14
101 £10.89 Up to £107.75
251 £10.26 Up to £427.48
501 £9.70 Up to £1,131.88
1000 £7.94 Up to £4,024.54

Product specification

Front Agar Type Nutrient TTC
Front Agar Colour Straw
Front Agar Growth Total Count (TTC / Red Spot)
Rear Agar Type Malt Extract
Rear Agar Colour Brown
Rear Agar Growth Yeasts & Moulds
Shelf Life 6 to 8 months
Certification ISO 9001

Cooling water dip slide tests

It is important to test the 'general health' of cooling water. You can do this using our cooling water (Nutrient and Malt Extract Agar) dipslides . These slides test for total count bacteria and yeasts and moulds. Although these displides will not test for legionella specifically, they will indicate if you have large bacterial growth which could potentially make the water a breeding ground for legionella or it could indeed contain the bacteria. As detailed in our article 'Dipslides for legionella testing

"If bacteria is present, we suggest that you conduct further tests to see if Legionella is one of the organisms in the system. Even if legionella is not identified, the presence of other organisms can support legionella by producing the organic nutrients that it needs to thrive.''

Regular dipslide tests are recommended (weekly) as well as routine quarterly legionella lab tests.

Flexible paddle

Flexible Paddle

Each dipslide features a virtually unbreakable and flexible paddle allowing for even, full surface testing.

Easy run off design

Easy Run Off Design

Due to the design of the dipslide, fluids will drain off quickly during testing.

Recessed Handle

Recessed Handle

Each slide has a handle built into the lid that is recessed to help keep your fingers dry during testing.

Side Indicator

Side Indicator

One side of the slide will have a circle indicator so you know which side was used for testing which type of contaminant.

Dual sided paddle

Dual Sided

Each dipslide is dual sided to allow multiple contamination testing with one test.

Thick reliable Agar

Thick Reliable Agar

Each agar is thick (approx 4mm) and raised above the dipslide to allow for easy surface testing.

How to use the cooling water dip slide test

Simply remove the dipslide and immerse in the cooling tower water sample for approx 10 seconds. Remove dipslide and allow to drain for a few seconds, then replace the slide back into the tube and incubate for a minimum of 24 hours (up to a maximum of 48 hours).

A comparison chart is included so you can easily compare your results.

Remove cooling water slide from tube

Step 1 : Remove slide

Carefully remove the sterile cooling water dip slide from its tube ensuring that no contact is made with the agar (to avoid contamination).

Surface testing

Step 2 : If Surface Testing

For surface testing, press the cooling water dipslide onto the surface. If needed, place a finger on the bottom of the slide (on the plastic, not the agar) to apply extra pressure.

Liquid Testing

Step 2 : If liquid testing

For liquid testing, immerse the cooling water dipslide into the fluid for 10 seconds then remove and allow to drain for a few seconds.

Swab Testing

Step 2 : If swab testing

Apply a sample of the test substance to a sterile swab and gently apply to the agars.

Incubate the dipslide

Step 3 : Incubate Slide

Label the tube with the included stickers then place the slide into an incubator and allow to incubate.

compare dipslide results

Step 4 : Compare results

Count the amount of colonies that have grown on the slide and compare them to the comparison chart provided.

Reading the results

Nutrient Side

Level of infection in liquids







Approx colonies per agar







HSE.gov.uk advice for evaporative cooling systems

System under control:

general microbial control and
no action required

Caution: Review programme operation:

Ensure the water treatment programme and system operation is operating correctly. Adjust the biocide dosage if appropriate and resample after 24 hours.

Action: Review programme operation and implement corrective action:

As a precaution, the system should be shot dosed with an appropriate biocide or the level of continuous dosage of biocide should be increased. The system should then be resampled after 24 hours to determine the effectiveness of the corrective action. If the high count persists, the control measures should be reviewed and the risk assessed to identify any necessary remedial actions.

Example Image

102.jpg 103.jpg 104.jpg 105.jpg 106.jpg 107.jpg

Level of infection on surfaces

0.4 2.5 12 40 100 250

Malt Extract Side

Level of yeasts in liquids







Approx yeasts colonies per agar







Example Image

Yeast dipslide growth Yeast dipslide growth Yeast dipslide growth Yeast dipslide growth Yeast dipslide growth Yeast dipslide growth

Level of yeasts on surfaces







Malt Extract Side

Level of moulds




Example Image

Light mould growth on slide Medium mould growth on slide heavy mould growth on slide

Industry sectors

  • Industrial cooling towers
  • HVAC systems

These facilities can be based at a multitude of locations such as:

  • schools
  • offices
  • hotels
  • hospitals
  • residential / care homes
  • plants
  • refineries

This kit will help you comply with:

New York Regulation: 10NYCRR 4-1 Maintenance Program

'(1) a schedule for routine bacteriological culture sampling and analysis to assess microbiological activity at intervals not to exceed 30 days while the cooling tower is in use, and that requires additional bacteriological culture sampling and analysis, as needed, to validate process adjustments;'

Please note, you will also be required by NY law to conduct specific legionella culture tests within 14 days of seasonal start up and at least every 90 days thereafter.

More information: https://regs.health.ny.gov/content/section-4-14-maintenance-program-and-plan

HSE ACOP L8 Maintenance and Testing Guidelines

The ACOP L8 documentation (http://www.hse.gov.uk/pUbns/priced/l8.pdf) refers to document 'Part1: The control of legionella bacteria in evaporative cooling systems' (http://www.hse.gov.uk/pUbns/priced/hsg274part1.pdf) for further technical guidance on cooling systems and how to comply with regulation.

Weekly dipslide / microbiological tests are recommended. Specific legionella culture tests should be conducted at least quarterly.


Specific References


BTM2 Datasheet

BTM2 Dipslide Datasheet (PDF)

Download (1.75M)

Malt Extract Comparison Chart

Malt Extract comparison chart in JPG format

Download (1.77M)


MSDS Sheet for Dipslides

Download (278.29k)

Nutrient Comparison Chart

Nutrient comparison chart in JPG format

Download (1.62M)