How Often Should You Replace Hot Tub Filters? (Inflatable vs. Acrylic)
The filter is the kidney of your hot tub. It works silently in the background, trapping body oils, hair, dead skin, and environmental debris. But unlike a kidney, it doesn’t heal itself.
If you ignore your filter, you aren’t just risking cloudy water; you are risking the life of your pump. A clogged filter restricts water flow, causing heater errors (like the dreaded E90 code) and motor burnout.
For Inflatable Hot Tubs (Intex/Coleman): Rinse your filter cartridges weekly and replace them every 2 to 4 weeks depending on usage.
For Hard-Shell Hot Tubs: Rinse weekly, deep clean chemically every month, and replace the filter cartridge every 12 months.
1. Why Inflatable Tubs Need Frequent Changes
Many new owners of inflatable hot tubs are shocked to learn they need to buy filters so often. The reason lies in the design.
Filters for inflatable spas (like the Type S1 for Intex or Type VI for Coleman) are significantly smaller and made of thinner paper pleats than the robust filters found in acrylic spas. They saturate quickly.
| Feature | Inflatable Tub (Type S1/VI) | Hard-Shell Tub |
|---|---|---|
| Surface Area | Small (Low capacity) | Large (High capacity) |
| Rinse Schedule | Every 3-5 Days | Weekly |
| Replacement | Every 2-4 Weeks | Every 1 Year |
2. The “Rinse, Soak, Rotate” Method
To extend the life of your filters and save money, you should adopt the “Rotation Method.” This involves owning two sets of filters.
- Rinse: Remove the dirty filter and blast it with a hose. Do not use a pressure washer, as this will tear the paper pleats.
- Soak: Place the rinsed filter in a bucket with a specialized filter cleaning solution (degreaser) for 24 hours. This breaks down the oils that water alone cannot remove.
- Rotate: While Filter A is soaking, put Filter B into the hot tub. Never run the tub without a filter.
Filter Cartridge Cleaner Tool
Stop using your thumb over the hose. This comb-like attachment sprays water deep between the pleats to dislodge debris without damaging the filter fabric.
Check Price on Amazon3. Signs It Is Time to Replace
Even with cleaning, filters eventually die. According to The Cover Guy, you should look for these signs of failure:
⚠️ Visual Inspection Checklist
- Discoloration: If the filter remains brown or gray after a chemical soak, the fibers are permanently stained with biofilm and oils.
- Fraying: Look at the paper pleats. If they look “fuzzy” or are separating from the plastic end caps, the structural integrity is gone.
- Core Collapse: If the plastic inner core is bent or warped, water flow is being restricted.
If you see these signs, replace the filter immediately. A $10 filter is cheaper than a $150 heating pump.
Intex Type S1 Filter Cartridges (12 Pack)
If you own a PureSpa, buy these in bulk. Since you need to change them every 2 weeks during peak season, a 12-pack ensures you never run your pump with a clogged filter.
Check Price on AmazonComparison: Intex vs Coleman Maintenance Costs
4. Biofilm: The Filter Killer
Sometimes, filters clog within days of being replaced. This isn’t a filter problem; it’s a plumbing problem.
Biofilm is a bacterial slime that lives in your pipes. When you turn the jets on, it coats your new filter in slime, blocking flow immediately. If you are burning through filters too fast, you need to purge the lines.
5. Pro Tips for Longevity
Want to clean your filters less often? Keep the dirt out of the water in the first place.
- Shower Before Soaking: Makeup, lotions, and deodorant are the #1 cause of filter clogging.
- Use Scum Absorbers: These sponges float in the water and collect oils so your filter doesn’t have to. Check out our top picks here.
- Shock Regularly: Oxidizing the water helps break down organic waste into gas, relieving pressure on the filter.
Final Thoughts
Maintaining your filter is the single most important task for hot tub longevity. Establish a routine: Rinse weekly, Soak monthly, Replace yearly (or bi-weekly for inflatables).
Looking to upgrade to a tub with better filtration? See our guide to the Best Inflatable Hot Tubs of 2025.
