How to Clean and Maintain a Hot Tub Filter

The hot tub filter is one of the most important parts of your hot tub. Bathers carry in oils, hair, and debris into the hot tub and it is important to keep the water healthy. The hot tub filter is responsible for keeping hot tub water clean and clear, as well as preventing microorganisms from growing inside your spa. If you want to keep your spa looking great and working properly, then it's a good idea to follow this guide on how to clean and maintain a hot tub filter.

Types of Hot Tub Filters

Before you dive into cleaning your hot tub filter, you must understand what type of filter you have and how it works.

Cartridge Hot Tub Filter

Cartridge hot tub filters are the most simple to clean and replace. There is a cartridge inside the filter housing that removes dirt and debris from your hot tub water as it goes through this media. Cleaning these filters simply requires removing them and rinsing off the particles stuck to the surface with a garden hose. Be sure to spray between the pleats and other crevices to remove all debris and algae. If the filter cartridge is especially dirty, it may require soaking in a filter cleaner to restore it.

Inspect the cartridge each time for tears or cracks. If you notice this type of damage to the cartridge it is time to replace it with a new hot tub cartridge filter. Once the filter is clean, inspect the O-ring on the filter tank and apply some lubricant to help maintain its effectiveness.

Ceramic Hot Tub Filter

Ceramic hot tub filters are a popular replacement option for common paper filters because they are durable and will last for 3-5 years. Cleaning these filters is as simple as a spraying a filter cleaner on them and spraying with a water hose. Some people even place ceramic hot tub filters in their dishwasher for a deep clean. 

D.E. Pool Filter

There are a couple of different ways to clean a D.E. hot tub filter. They can be chemically cleaned and can also be backwashed. If you are conducting normal monthly  filter cleaning, chemically cleaning your filter should be sufficient. if your water is cloudy, a deep cleaning is in order.

Regular cleaning is quick and easy. Simply follow the steps below:

• Backwash the filter for a few minutes to remove loose debris.
• Remove the filter manifold and each grid.
• Rinse the tank.
• Use a garden hose spray nozzle to clean the manifold. If spraying with water isn't sufficiently cleaning it, use a filter cleaner.
• Spray down the grids, removing all of the D.E. powder.
• Re-assemble.

Once a year your D.E. filter will likely require a deep cleaning with muriatic acid. Take protective precautions, as muriatic acid is toxic. Follow these steps:

• Backwash the filter for a few minutes to remove loose debris.
• Remove the filter manifold and each grid.
• Rinse the tank.
• Use a garden hose spray nozzle to clean the manifold. Put on your protective equipment (goggles, gloves, etc). Dilute the muriatic acid according to the manufacturer's instructions. Soak the manifold in the acid overnight.
• Spray down the grids, removing all of the D.E. powder.

Once the filter is clean, you will need to add new D.E. powder to the filter. Follow the instructions on the D.E. powder for mixing and application.

Sand Hot Tub Filter

To maintain a sand hot tub filter, backwash the filter regularly to maintain clear, clean  water. If you notice that backwashing is not sufficiently cleaning the filter, it may be time for a chemical clean.

• Backwash the filter to remove loose debris.
• Pour sand filter cleaner into the strainer basket and replace the lid.
• Turn the pump on for 10-15 seconds to transfer the cleaner into the filter.
• Let the cleaner sit in the filter overnight.
• Backwash the filter again.

If your filter is damaged or too dirty to clean, consider investing in a new filter. Without a hot tub filter working at optimal performance, your hot tub will continue to be dirty and be unbalanced.