Cam Lock Spa Pool Filters vs Threaded Filters. What’s the Difference?

If you’re maintaining or upgrading your spa pool, you’ll eventually come across two common types of filter connections - cam lock and threaded.

Understanding the difference between them helps you choose the right replacement cartridge and avoid common installation issues.

What is a Cam Lock Spa Pool Filter?

A cam lock (also known as bayonet or twist lock) filter features a smooth base with a locking mechanism rather than screw threads.

To install it, you simply insert the filter into the housing, align the fitting, and give it a short quarter-turn to lock it into place. Removal is just as easy, twist in the opposite direction and lift it out.

Benefits of Cam Lock filters:

• Quick and easy to install or remove

• No risk of cross threading or stripped threads

• Ideal for frequent cleaning or filter swaps

• Great option if your spa has limited access space

Cam Lock filters are increasingly common in modern spa brands like Vortex® Spas. They offer a simple, tool free way to secure your cartridge and make regular maintenance faster.

What Is a Threaded Filter?

A Threaded filter (either coarse or fine thread) screws directly into the filter housing. It’s been the traditional connection method used in many spa models for years.

Benefits of Threaded filters:

• Very secure fit once tightened

• Widely available across most spa models

• Familiar and proven design

However, threaded filters can be more difficult to install correctly. It’s easy to misalign the threads or over tighten the cartridge, which may cause damage over time. Worn or stripped threads can also prevent the filter from sealing properly, leading to water bypass or leaks.

Key Differences Between Cam Lock and Threaded Filters

Using Adapters to Convert Between Filter Types

If your spa was originally designed for a threaded filter, but you’d like to switch to a cam lock style, you don’t need to replace the entire housing — you can use a filter adapter.

The adapter simply screws into your existing threaded housing and provides a cam lock fitting on top.
Once installed, you can use any compatible cam lock filter cartridge.

This small upgrade saves you from replacing the entire filter housing and makes future filter changes quick and hassle free.

Which Type Should You Choose?

If you’re buying a new spa or upgrading your filtration system, cam lock filters are usually the easier and more user friendly choice.
If you already have a threaded housing that’s still in good condition, there’s no urgent need to change, but if the threads are worn or replacements are hard to find, using a Cam Lock adapter is an excellent long-term solution.

To find the right cam lock or threaded filter for your spa or to get a compatible adapter, check your filter’s base connection type or contact us for help.