Drain Cleaner Granules – Clear Flow CS20

(20 customer reviews)

Our easy-pour drain granules use less chemicals per dose and requires less shipping than regular brands. 

Why should you buy our drain cleaner granules?

  • Our powerful, fast-acting drain unblocker granules are the top choice for rapid blockage removal.
  • Industrial strength, caustic-based drain crystals that are designed for commercial premises.
  • Quickly breaks down fats and removes grease from blocked drains.
  • Gentle on pipework.
  • Easy-pour container for safe, simple application.
  • Powerful, eco-friendly, solvent-free formula.

Sizes: 12 x 500g granules

FREE delivery to mainland UK when you spend £100 with us. For delivery to Northern Ireland, the Isle of Man, the Isle of Wight or the Scottish Highlands, contact our sales team via our live chat.

£49.77 for 12 x 500g

Additional information

Weight N/A

500 grams, 12 x 500 grams

Additional information

Weight N/A

500 grams, 12 x 500 grams

Product Information

Clear Flow CS20 drain cleaner granules are the first-choice for UK businesses. From food preparation to abattoirs, engineering works, laboratories, local authorities, health trusts, and nursing and care homes – all industries benefit from our fast-acting drainage cleaner.

Why should you choose our drain cleaner granules?

  • Break down oils, fat, grease, hair and food waste to remove blockages.
  • The granulated form makes our drain cleaner easy to use, reducing the chances of spillage.
  • Take up less room than liquid drain cleaners, helping you maximise precious storage.
  • They’re cheaper – As our drain cleaner granules are solid and don’t contain water, you’re paying us to ship the product and nothing more.
  • Ultra-concentrated formula means you need to order less frequently.
  • Easy pour and leave technology – Just leave for 30 minutes and add water.
  • Helps you make efficiency savings – Our easy application method means maintenance crews don’t need to spend longer than a few minutes on each blockage.

Not sure which drain unblocker you need? Get in touch with us to speak to one of our UK-based drain cleaner experts.


How to use our drain clear granules?

  1. Wear appropriate alkali-resistant protection for skin and eyes in accordance with HSE guidelines.
  2. Remove excess water from the drain using a ladle or siphon.
  3. Pour up to 500g of Clear Flow CS20 drain cleaner granules directly into the drain or grease trap, depending on the severity of the blockage.
  4. Add warm water (if available) but don’t overfill the drain.
  5. Cover the drain and allow it to work for up to 30 minutes.
  6. Repeat if required.

Always check the label before use.

Dilution Rates

Use as per the above instructions


  • Caustic-based

Drain Unblocker Granules FAQ's

How do drain cleaner granules work?

Our Clear Flow Drain Cleaner Granules are caustic-based. This means they’re easy-to-use and can quickly break down fats, oils, grease, hair, and food waste from blocked drains without damaging pipework.

They work by speeding up the decomposition and of hair, oil, grease-causing matter. Once water is added, the granules can penetrate through clogs and other liquids.

We also stock:

Can this drain cleaner be used on all types of drains?

Yes, it can.

Our drain clear granules and crystals are specially formulated to be safe for use on all pipework.

You can use our Clear Flow CS20 Drain Cleaner Granules on kitchen sinks, grease traps and bathroom drains. You can even use our drain cleaner outside on tougher blockages.

Can our drain cleaning granules be used as a preventive measure?

Yes. We recommend using our drainage block cleaners as part of your regular cleaning and maintenance schedule to prevent clogs from forming and keep drains running smoothly.

How long does it take for our drain block cleaner granules to work?

Our drain cleaner gets to work in as little as 30 minutes, depending on the severity of the clog.

If needed, repeat the process until the blockage is clear.

What should I do if the clog does not clear after your drain cleaner granules?

In the unlikely event that our drain clear granules don’t clear the blockage, seek professional help.

If you’re looking for a reputable commercial cleaning business, our sister company – APT-ICC – is highly recommended.

How do I use your drain cleaner granules to unblock a drain outside?

Although caustic soda is often used for outside drains, it’s not the most effective solution for unblocking drains as it can often eat through the pipe itself. This can be costly and time-consuming for your organisation.

When it comes to unblocking an outside drain, we recommend using our industrial strength drain cleaner granules – Clear Flow Granules. This is because they have been specially formulated to take care of your pipework.

To use our outdoor drain unblocker, all you need to do is:

  1. Ensure appropriate PPE is worn.
  2. Pour up to 500g of Clear Flow CS20 drain cleaner granules directly into the affected drain.
  3. Add warm water (if available) but don’t overfill the drain.
  4. Cover the drain and allow to work for up to 30 minutes.

Repeat the process until the blockage has fully cleared.

Can you put drain cleaner granules down the toilet?

We do not recommend putting our drain cleaner granules down the toilet.

This is because our drainage pipe blockage cleaner granules have been designed for use in industrial drains and grease traps.

We have a range of specially formulated toilet cleaning products that are more suitable for the task at hand. Our highly-concentrated washroom products include:

  • Bi-Active – Disinfectant & Hard Surface Cleaner – all-in-one washroom disinfectant and hard surface cleaner.
  • Descale – Toilet Cleaner & Descaler – all-in-one thickened toilet cleaner, disinfectant and descaler, with added fresh long-lasting fragrance.
  • Bleach Tablets – powerful chlorine bleach tablets.
  • Zest Fresh – citrus fragrant toilet cleaner, limescale remover and disinfectant.

How soon will I get my drainage cleaner

When you place an order with APT Chemicals, we know time is of the essence. We’ll always strive to get your drain cleaner granules to you as quickly as possible.

Once you’ve placed your order, we’ll send you a confirmation email with an estimated delivery date.

We endeavour to get your order to you the next-day provided that your order is placed by 12pm. In the current climate, we ask that you allow up-to 3 days. Please note that these delivery dates are estimates and are subject to change based on factors such as product availability and shipping carrier delays.

We also offer free shipping on orders over a £100, if you’re based in mainland UK. For delivery to Northern Ireland, Isle of Man, Isle of Wight or Scottish Highlands, please contact our sales team for a shipping cost.

Please refer to our shipping policy for more information on free shipping eligibility.

If you have any questions or concerns about your order, speak with our customer support team via our live chat.

Do you accept returns?

Yes, we do.

If, for whatever reason, you need to return your drainage cleaning granules, doing so is easy thanks to our no-quibble returns policy.

All you need to do is:

  • Email sales@apt-icc.co.uk with your:
    • Name
    • Company Name & Address
    • Reason for requesting a return of the item and photographs should they be relevant
  • On receiving acknowledgement, please pack your items in the original packaging and send them back to us within 14 days.
  • Send the items to us using recorded delivery or any method that provides proof of return.
  • We will aim to process your return within one week.

See more information on our returns policy and 100% Money Back Guarantee, see our Terms and Conditions.

20 reviews for Drain Cleaner Granules – Clear Flow CS20

  1. aptcommercialchemicals

    I’ve trusted APT’s Drain Granules for years, and they’ve never disappointed. They recently tackled a bathroom sink clog effortlessly. The eco-friendly aspect is a bonus.

  2. aptcommercialchemicals

    APT’s Drain Cleaner Granules are my first choice for drain issues. They work efficiently and are kind to the environment. Recently, they cleared a persistent shower drain blockage.

  3. aptcommercialchemicals

    I manage a commercial kitchen, and APT’s Drain Granules are a lifesaver. They quickly dissolve grease, ensuring smooth drainage. I love that they’re gentle on pipes.

  4. aptcommercialchemicals

    Running a bakery, we deal with lots of grease. APT’s Drain Granules are our go-to solution for keeping our drains clear. They’re industrial-strength and eco-friendly, a perfect combo.

  5. aptcommercialchemicals

    I’m a loyal user of APT’s Drain Cleaner Granules. They’re powerful yet safe for pipes. A recent clog in my utility sink was no match for them. Always reliable!

  6. aptcommercialchemicals

    Being eco-conscious, I appreciate APT’s Drain Granules. They’re effective and don’t harm the environment. They recently cleared a persistent bathroom sink blockage.

  7. aptcommercialchemicals

    I had a blocked shower drain, and APT’s Drain Granules came to my rescue. They cleared the clog quickly without harming my pipes. Great product!

  8. aptcommercialchemicals

    We had a drain problem at our hotel, and APT’s Drain Cleaner Granules were a lifesaver. They’re industrial-strength and environmentally friendly, making them perfect for our business.

  9. aptcommercialchemicals

    I’ve been using APT’s Drain Granules for years, and they consistently perform well. Recently, they resolved a kitchen sink blockage effortlessly. The eco-friendly aspect is a bonus.

  10. aptcommercialchemicals

    Running a busy restaurant, we can’t afford drain issues. APT’s Drain Cleaner Granules are our secret weapon. They swiftly tackle grease and maintain smooth drainage, crucial for our kitchen’s efficiency.

  11. aptcommercialchemicals

    Our cafe had a drain blockage, and APT’s Drain Cleaner Granules did the job perfectly. They dissolve fats quickly, keeping our drainage system trouble-free. Plus, they’re eco-friendly, which aligns with our values.

  12. aptcommercialchemicals

    A recent bathroom sink blockage had me worried, but APT’s Drain Granules saved the day. They’re gentle on pipes and incredibly effective. A must-have for any homeowner!

  13. aptcommercialchemicals

    I manage a commercial kitchen, and our drains often get clogged with grease. APT’s Drain Cleaner Granules are our go-to solution. They’re industrial-strength and never damage our pipes.

  14. aptcommercialchemicals

    As a homeowner, I trust APT’s Drain Granules for my drain issues. They’re not only effective but also eco-friendly. Recently, my shower drain was blocked, and these granules cleared it in no time.

  15. aptcommercialchemicals

    I’ve used APT’s Drain Cleaner Granules for years, and they never let me down. Recently, our bathroom sink was clogged, and these granules worked like magic. They’re safe for pipes and the environment.

  16. aptcommercialchemicals

    Running a restaurant, I need a drain cleaner that’s tough on grease. APT’s Drain Granules never disappoint. They efficiently dissolve fats and keep my drains flowing smoothly. Plus, it’s eco-friendly—a win-win for my business.

  17. aptcommercialchemicals

    We had a stubborn kitchen sink clog, but APT’s Drain Cleaner Granules came to the rescue. The easy-pour container made application a breeze, and it quickly cleared the blockage without damaging my pipes. Impressive!

  18. Guest

    Worked effectively on our drains, will be purchasing from APT again.

  19. Guest

    Saved us a lot of time and money, and a lot doesn’t need to be used to get the job done.

  20. aptcommercialchemicals

    Our leisure centre pipes had become completely blocked and the waste water was coming back up into the showers. We had tried all the usual drain unblockers, plungers, hot water and were resigned to pay out a lot of money to get someone in to clear the pipes. Tried this as a last resort, we cleared excess water from showers, poured the liquid into the drains through the plug hole and left overnight. In the morning, a kettle of boiling water was poured down each plug hole. This stuff cleared our pipes!! Would definitely give this a go before you call someone in. If we have anymore blockages I would 100% use this stuff again.

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Contact us today via email sales@apt-icc.co.uk or free phone 0800 0723 773


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(20 customer reviews)

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