Pleatco X18-PHY25 Filter for Hydropool Serenity Spas

Pleatco X18-PHY25 Replacement Spa Filter for Hydropool Serenity Series Hot Tubs

The Pleatco X18-PHY25 spa filter cartridge is a high-quality replacement filter designed for select Hydropool Serenity Series hot tubs manufactured around 2020. These filters were used to replace the larger Serenity Wave Filter P/N 4520035 and help maintain cleaner water, improved circulation, and efficient filtration performance.

Two Pleatco X18-PHY25 filters are required for compatible spa models. These are push-on style filters and some Hydropool spas may require the Hydropool sleeve adaptors P/N 5005045 for proper installation. Adaptors are sold separately.

Please note: If your Hydropool Serenity Series spa uses threaded filters instead of push-on filters, you will likely need the 6CH-940 replacement filters instead.

Features & Benefits

• Genuine Pleatco replacement spa filter
• Replacement for Hydropool X18-PHY25 filters
• Replaces Serenity Wave Filter P/N 4520035
• Designed for select 2020 Hydropool Serenity Series hot tubs
• Helps improve water clarity and circulation
• Efficient pleated filtration media
• Helps capture dirt, debris, oils, and contaminants
• Durable construction for long-lasting performance

Important Fitment Information

• Uses push-on style filter connection
• Two filters required per spa
• Some models may require:
  • Hydropool Sleeve Adaptors P/N 5005045
• Adaptors sold separately
• If your spa uses threaded filters:
  • Search for 6CH-940 filters instead

Maintenance Tips

For best filtration performance, rinse your spa filters every 2–4 weeks and deep clean regularly with a dedicated spa filter cleaner. Replace filters approximately every 12 months depending on water chemistry, spa usage, and maintenance routine.

Why Buy From Red Rock Spas?

Red Rock Spas is a real spa dealership and service company serving Utah and Nevada. Our team works on hot tubs daily and helps customers verify the correct replacement filters, water care products, and spa parts using real-world experience.

Need Help Finding the Correct Filter?

Contact our team and we can help verify compatibility for your Hydropool spa before ordering.