5 Hot Tub Filter Problems
Spa filters are the kidneys of your spa water, removing impurities and particles to keep systems working. If you were to run your spa without a filter, even a covered spa will quickly deteriorate in water quality.
And that's exactly why you are here, searching for solutions to your vexing hot tub filter problems, and related water quality issues. So without further ado; here are the top spa filter problems and what to do about them.
stained spa filters
A stained filter may not be a bad thing, if it doesn't affect filter capacity, or even dirt distribution, or length of time between cleanings. Metals such as iron can stain a filter with a light brown orange stain. You may find your filter looking gray, green, yellow or even purple at times.
For spa filter stains that don't hose off easily, the best thing is to give the filter a good cleaning in a good spa filter cleaner. This will remove oils and minerals and most metal stains from hot tub filter cartridges. Never use acid, bleach or other cleansers that contain soapy phosphates; you'll never get it out and suds your tub.
If some stains remain after soaking and rinsing, these may not affect the ability of the filter cartridge, but depending on thickness, heavy stains can reduce the microscopic filter pore size to the point where areas of the cartridge are not utilized.
The better question may be - what is it that stains the cartridge? Is it in the water like metals or an algae, or a byproduct of certain chemical combinations? Are calcium hardness and pH levels high? Do you need to prefilter your fill water?
holes in spa filters
Back when I was servicing hot tubs for a living, I was cleaning a filter cartridge and noticed it had stitches. The lady of the house told me that she had 'stitched them up!', very proudly. OK, but for the rest of us a replacement cartridge is in order if holes are noticed. Even very small holes will reduce your filter effectiveness.
The better question may be - what caused holes in the cartridge? In this case, the lady of the house had, unbeknownst to her, a large pool pump installed on a small spa filter. It had blasted holes the size of a pencil in the spa filter cartridge. I've also heard tale of certain insects that have a taste for spun polyester, so store your spares accordingly.
cracked spa filters
When you speak of a cracked spa filter, what is usually meant is that one of the colored rubber end caps has developed a split or crack. Spa filters can also crack across the central support cage. Both instances are rare, but if your spa filter has a crack in either end (not tiny crazing, but real splits) you will need to replace the cartridge.
The better question may be - what caused the end cap to crack in the first place? Could be the same as for holes in spa filters, a crack in the end cap could result from a spa filter pump that is too large for the filter size. Cracks or holes can also happen from closing a valve after the filter while the pump is running, or in some cases when an undersized filter is extremely dirty.
fuzzy spa filters
The tips of your pleated fabric, are they smooth and relatively fur-free? In some cases, spa filters can become fuzzy on the pleats and this can reduce your filter's ability to trap dirt by reducing the spaces between pleats. It also creates a lot of turbulence for the water and dirt, as it enters the pleats (on a small scale).
Why does the spa filter cartridge seem to unravel at the edges? It's usually from chemical problems in the spa, poor water balance or high sanitizer levels. It's also caused by cleaning the cartridge with too much water pressure. A new spa filter is in order.
clogging spa filters
Does your spa filter clog up again in a few days after cleaning? That's not gonna work, in most cases a 2-4 week filter cycle can be expected, depending on the size of the filter cartridge, and how much the spa is used, and to some degree as mentioned above, the water balance.
A filter that clogs up quickly is likely coated with mineral scale, oily films, or both. A cleaning with spa filter cleaner is in order to unclog the microscopic passageways between the fibers of the filter. TSP can also be used for oily filters, but it won't remove mineral scale from hard water.
If your filter is still clogging quickly after cleaning, it's probably best to replace it, even if it's relatively new. Assuming that it's sized properly for the pump and installed properly, the filter cartridge lose life quickly when cleaning certain substances from the hot tub water.
The better question is - what vegetable, oil or mineral is clogging the spa filter?
- Hot tub filter cartridges naturally degrade over time, the woven fibers separate and they are unable to filter the smaller particles. Or, filter cartridges become coated with oily and crusty deposits which are hard to remove, causing them to clog quickly. Replace your spa filter every 12-24 months.
- A few things you should not do - don't put your spa filter in the dishwasher, and don't use a pressure washer to clean it. Just hose it clean, soak it in one of our many spa filter cleaners, and rinse it clean again.