Keep your hot tub water sparkling clean with the ProAqua Rainbow 50 Sq. Ft. Replacement Filter Cartridge. Designed for superior filtration performance, this high-capacity cartridge captures dirt, debris, body oils, and other contaminants before they can affect water quality or spa performance.
Manufactured with premium pleated filtration media, the Rainbow 50 filter provides excellent water flow while maximizing dirt-holding capacity. Its larger 50 sq. ft. filtration area helps maintain cleaner water for longer periods between cleanings, making it an ideal choice for high-use spas and hot tubs.
Whether you're replacing an aging filter or keeping a spare on hand, the ProAqua 40505 delivers dependable OEM-quality performance to help protect pumps, heaters, and circulation systems while ensuring a cleaner and more enjoyable spa experience.
Key Features
✔ 50 square feet of filtration area
✔ Premium pleated filtration media
✔ Improves water clarity and cleanliness
✔ Captures dirt, oils, and fine debris
✔ High dirt-holding capacity
✔ OEM-quality replacement performance
✔ Easy to clean and maintain
✔ Durable construction for extended filter life
Specifications
| Specification |
Details |
| Filter Area |
50 Sq. Ft. |
| Diameter |
4-15/16" |
| Length |
13-5/16" |
| Top Opening |
2-1/8" Open |
| Bottom Opening |
2-1/8" Open |
| Filter Type |
Replacement Cartridge |
Always verify dimensions and end cap configuration before ordering.
Compatible Spa Brands & Models
This filter is commonly used in:
Waterway Rainbow Dynamic Systems
- Rainbow Dynamic 50 Filtration Systems
- Waterway Top Load 50 Filtration Systems
Compatible Spa Brands
- Bullfrog Spas
- Clearwater Spas
- Coast Spas
- Leisure Bay Spas
- Sun & Soul Spas
- PDC Spas
- Viking Spas
- Waterway Plastics Spa Systems
- Select Sundance Spa Models
- Various private-label spas utilizing Rainbow Dynamic 50 filters
Always compare your existing filter dimensions and end-cap style to ensure proper fitment.
Cross Reference Part Numbers
This filter is compatible with and replaces:
- ProAqua 40505
- Pleatco PRB50-IN
- Unicel C-4950
- Filbur FC-2390
- Darlly 40506
- Waterway 817-0050
- Waterway 817-0500
- Rainbow Dynamic 50
- Aladdin 15006
- APCC7080
Why Replace Your Hot Tub Filter?
Regular filter replacement helps:
- Improve water clarity
- Increase filtration efficiency
- Reduce strain on pumps and heaters
- Improve sanitizer effectiveness
- Extend spa equipment life
- Maintain proper water circulation
For best results, rinse your filter every 2 to 4 weeks and perform a deep cleaning every 3 to 4 months. Replace your filter annually, or sooner depending on spa usage and water conditions.
Pro Tip
Keeping a second filter cartridge allows you to rotate filters during cleaning cycles. This ensures continuous filtration performance while extending the lifespan of both cartridges.
