The Oase Clear Water Guarantee is our promise to help you achieve beautifully clear pond water. If your water does not become clear and our experts cannot resolve the issue, we'll refund your purchase price.* 

Contact support.

*Terms and conditions apply. 

For over 75 years, Oase has helped pond owners create and maintain clear, beautiful ponds. 

Our filtration systems are designed, developed, and extensively tested in-house, drawing on decades of expertise in water gardening and filtration technology. Oase products are trusted by pond enthusiasts and professionals around the world. 

The Clear Water Guarantee reflects our confidence in the quality of our products, the knowledge of our technical support team, and our commitment to helping customers achieve beautifully clear pond water. 

Your Oase Clear Water Guarantee is automatically included when you purchase a qualifying Oase clear water system. 

A qualifying system includes an Oase pump, filter and UVC clarifier, correctly matched to your pond size and fish stock. 

If you experience a water clarity issue, simply contact our Technical Support team and we'll guide you through the next steps. 

Our pond experts are here to help. 

If your water isn't as clear as expected, contact our technical support team. We'll work with you to understand your pond setup, identify potential causes, and recommend practical solutions to restore water clarity.  
 
In most cases, issues can be resolved quickly with the right advice and a few simple checks. 
 
EN/US regions 
Email: enquiries@oase.com 
Phone: +44 (0) 1256 896886 

AUS 
Email: enquiries@oase.com 
Phone: +61 8 6260 1000 

DE/all other regions 
Email: garantie@oase.com 
Phone: +49 (0) 5454 / 933 949 -20 

Simple 3-step process: 

1. Install your qualifying Oase system  
   Install and operate your qualifying Oase system according to the instructions.  

2. Contact us if you need help  
   Contact our technical support team if you experience a water clarity issue.  

3. We’ll make it right  
   We'll work with you to diagnose and resolve the problem. If we can't, we'll refund your purchase price.* 
   

*Terms and conditions apply.  

The Clear Water Guarantee applies to a complete Oase clear water system. A complete system works as one, with each part doing a specific job: 

• A pump to circulate the water and feed it into the filter. 
  

• A filter to provide both mechanical and biological cleaning, removing debris and breaking down the nutrients that cloud water. 
  

• A UVC clarifier to clear the green from the water by treating the suspended algae that cause it. 
  
  

The guarantee applies when you use qualifying Oase products for all three parts, correctly sized for your pond volume and fish load. The right combination for your pond delivers clear water. You can see the qualifying products, and how to match them to your pond, in the sections below. 

Any pond can have an Oase clear water system, whether newly built or retrofitted to an existing pond. 

The Clear Water Guarantee is designed to help you achieve clear pond water using a complete, correctly sized Oase filtration system. It does not apply where water clarity is affected by circumstances outside the normal operation of the system, including: 

• Systems that are undersized for the pond volume or fish stock.  

• Filtration systems that combine qualifying Oase products with non-Oase pumps, filters or UVC clarifiers.  

• Incorrect installation, operation or maintenance.  

• Ponds that do not meet the qualifying pond conditions described in the Terms & Conditions.  

• External contamination or water quality issues caused by flooding, chemicals, construction work or similar events.  

• Equipment that has been modified or used outside the manufacturer's instructions.  

• If you're unsure whether your pond or equipment qualifies, our Technical Support team will be happy to help. 

Every pond is different, so the right filtration system depends on your pond volume and fish stock. 

The recommendations below show qualifying Oase clear water systems that meet the requirements of the Clear Water Guarantee when correctly installed, maintained and sized for your pond. 

These recommendations are based on normal installation conditions. Pipe length, waterfalls, streams and differences in height between the pond and filter can all affect water circulation. If your installation is more complex, our Technical Support team will be happy to help you choose the right system. 

Every pond is different, so the right filtration system depends on your pond volume and fish stock. 

The table below shows complete Oase clear water systems that qualify for the Clear Water Guarantee when correctly installed, maintained and sized for your pond. 

The systems shown above qualify for the Oase Clear Water Guarantee when correctly sized, installed and operated in accordance with the Clear Water Guarantee Terms & Conditions. 

Clear water means you can recognize fish, plants, and pond features below the water surface to a depth of 1 meter. 

Natural coloring, slight cloudiness, and thread algae are normal parts of a healthy pond and are not considered water clarity issues. Pond water is a natural environment and is not expected to be as clear as drinking water. 

My pond is newly installed 

New ponds need time for beneficial bacteria to establish and support biological filtration. During this period, some cloudiness is completely normal. 

Check: Has the system been running continuously for at least six weeks? 

My pond water is green  

Green pond water is usually caused by microscopic algae suspended in the water. This can occur in new ponds, ponds receiving excessive sunlight, or where UV clarification is not operating effectively.  

Check: Is your UV clarifier working correctly and receiving the recommended maintenance? 

My pond water is cloudy 

Cloudy pond water is often caused by suspended particles, biological activity in newly established ponds, or insufficient filtration.  

 Check: Is your filtration system correctly sized for your pond and operating continuously? 

My UV clarifier needs maintenance 

UV lamps gradually lose effectiveness over time, even if they still illuminate. Reduced UV performance can allow green water algae to develop. 

Check: When was the UV lamp last replaced? 

I clean my filter frequently 

A healthy filter relies on beneficial bacteria living within the filter media. Cleaning too often can disrupt this natural process and slow water clarification. 

Check: Are you cleaning the filter more often than recommended in the instruction manual? 

My pond contains a lot of fish 

Fish naturally add nutrients to the pond, which increases the workload on the filtration system. Heavily stocked ponds may require larger filtration systems or more frequent maintenance. 

Check: Is your filtration system correctly sized for your pond volume and fish stock? 

I feed my fish frequently 

Excess food can break down in the pond and contribute to nutrient build-up, encouraging algae growth and reducing water clarity. 

Check: Are fish consuming their food within a few minutes, without leftovers remaining in the pond? 

My pond receives a lot of sunlight 

Sunlight is essential for pond life, but prolonged exposure can encourage algae growth and affect water clarity. 

Check: Does your pond receive significantly more than 4–6 hours of direct sunlight each day? 

Water from the surrounding garden enters the pond 

Rainwater runoff can carry soil, fertilizers, and other nutrients into the pond, which may affect water quality. 

Check: Could surface water be flowing into the pond after heavy rainfall? 

Water circulation is limited 

 Good circulation helps move debris towards the filter and ensures water is treated throughout the pond. 

Check: Is water moving freely throughout the entire pond, including corners and deeper areas? Poor circulation may indicate that your filtration system is undersized or not optimally installed. 

My filtration system may be undersized 

 Filtration performance depends on matching the system to your pond size, fish stock and overall pond conditions. 

Check: Is your system correctly sized for your pond volume and fish load? Water circulation is also influenced by your pond layout, pipework, filter and UVC installation, and any water features. If you're unsure, our Technical Support team will be happy to help. 

Parts of my system may need replacing 

Like any filtration system, certain components wear over time and need periodic replacement to maintain performance. 

Check: Are filter foams, UV lamps and other service parts being replaced at the recommended intervals? 

My pump or filter is not running continuously 

Biological filtration relies on a constant flow of water through the system. Interruptions can reduce filter performance and delay water clarification. 

Check: Is the pump and filter system operating continuously (24 hours per day) throughout the pond season? 

How long does it take for pond water to become clear? 

New filtration systems can take up to six weeks to establish the biological processes required for clear water. During this period, some cloudiness is normal. 

Check: Has your system been running continuously for at least six weeks? 

The Clear Water Guarantee is designed for ornamental garden ponds and water gardens. 

To qualify, your pond must: 

✓ Be an artificial pond constructed using a pond liner or shell 

✓ Include aquatic planting covering at least one-third of the water surface 

✓ Receive approximately 4–6 hours of sunlight per day 

✓ Be located at least 4 meters away from deciduous and coniferous trees 

These conditions help create the right environment for effective biological filtration and clear pond water. 

To help your filtration system perform at its best, we recommend the following: 

✓ Using a qualifying Oase filtration system that is correctly sized for your pond 

✓ Using an Oase solids-handling pump, such as an AquaMax pump, where specified 

✓ Operating the pump and filter continuously (24 hours a day) throughout the pond season 

✓ Allowing up to 6 weeks for the filter biology to mature and the pond to clear 

✓ Using Oase filter starter bacteria, such as BioKick, during initial start-up and spring recommissioning 

✓ Following the installation, operation and maintenance instructions supplied with the product 

These requirements also form part of the Oase Clear Water Guarantee conditions. If you're unsure whether your pond or filtration system meets these requirements, our technical support team will be happy to help. 

Can I claim immediately after installing my system? 

No. New filtration systems require time for beneficial bacteria to establish. In some cases, it can take up to six weeks for water to become clear. 

Does the guarantee apply to existing ponds as well as new ponds? 

Yes. The guarantee applies to qualifying ponds and products when installed, operated and maintained in accordance with Oase recommendations. 

Does the guarantee cover green water and cloudy water? 

The guarantee covers water clarity performance. Our technical support team can help identify the cause of both green and cloudy water and recommend the appropriate solution.

What information will I need if I contact support? 

We may ask for information about your pond, equipment, fish stock, and maintenance routine to help us diagnose the issue. 

Why does Oase offer a Clear Water Guarantee? 

Because we're confident in the quality of our products, the expertise of our technical support team and our ability to help customers achieve beautifully clear pond water. 

In the unlikely event that we are unable to resolve your water clarity issue, you may be eligible to make a claim under the Oase Clear Water Guarantee. 

To assess your claim, we may request additional information about your pond, equipment, and installation. This helps us confirm that the guarantee conditions have been met and allows us to fully investigate the issue. 

If a claim is approved, you may be asked to provide proof of purchase and return the qualifying product for further inspection. 

Once the claim has been verified, Oase will refund the purchase price of your qualifying Oase products in accordance with the Clear Water Guarantee terms and conditions. 

Every pond is different. If you'd like help assessing your pond, equipment or water clarity issue, our technical support team will be happy to help. 

EN/US regions 
Email: enquiries@oase.com 
Phone: +44 (0) 1256 896886 

AUS 
Email: enquiries@oase.com 
Phone: +61 8 6260 1000 

DE/all other regions 
Email: garantie@oase.com 
Phone: +49 (0) 5454 / 933 949 -20 

For more information about eligibility, guarantee conditions and claims, download the full Oase Clear Water Guarantee terms and conditions. 

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