Written by Terry Smith
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Best hot tub filter system: UK Top hot tub filters – external and paper compared
This article was last updated on July 31st, 2021 at 1:47 am
Hot tubs are a great addition to the garden and are good fun for family and friends, but keeping it clean can be a real pain and can take the fun out of it for sure! Anytime I’ve used a hot tub it’s great for the first few days and then once it starts getting dirt or debris in, it becomes a fuss to clean. A quick net job gets the larger stuff out, but what about the smaller gross stuff that gets in there too?
Well, that’s where a hot tub filter system comes in. They’ll ensure that your hot tub keeps clean, but they can be quite specific and it’s important you get the right one. On top of this, there are paper and external filters, so you need to know how they work. Don’t worry though, we’ve got it explained below and also reviewed the best hot tub filter systems out on the market currently, as well as a handy buyers guide to help you decide what’s right for you!
What is a hot tub filter system?
Whether it’s an inflatable tub or a hardware tub there’s quite a few cleaning components you’ll need, including a hot tub filter system. You have your hot tub chemical kits to keep it sanitised and ready for use, as well as a heating system, but a filter system is basically used to collect the gross stuff that you can’t grab yourself with a net. On top of this, any liquids or oils that it collects with use (grim I know!) will get filtered out, leaving just clean water.
Paper filters are just your standard pool/spa filters that quite literally are made from waterproof paper that filter everything out and that drain the water efficiently. This eventually needs to be cleaned, say every couple of weeks of use, to make sure that it doesn’t build up so much that it returns to the water. They’re cheaper than external/electric filter pumps but they need to be replaced, as well as being more suited for hardware tubs rather than inflatable, but they’re pretty key to all hot tubs no matter what.
Electric pumps on the other hand just use power (and filter paper) to channel the water through the pump to clean it and then back into the tub. They’re more expensive, and chances are you’ll need filter paper, but they’re great for inflatable tubs and I would say are way better than just using paper filters.
Whether you just use paper or go for an electric pump, hot tub filters look so complicated when you first look them up and they all seem specific to different tub models. This makes buying them a lot more confusing, which I realised when looking recently to replace mine. After some research though, it became clear that actually the filters are all so similar that as long as they’re the same size as your tub they’ll work, so just measure everything beforehand (important!).
With that in mind, we purchased a few different filters and below we’ve ranked the best ones out there, so you should hopefully figure out which is best for you. We’ve compared both paper and external filters too, so you should know which would suit you and your hot tubs needs more. With the right filter, hot tubbing is a lot more enjoyable!
Best Hot tub Filter System
- Bestway Filter Cartridge I (3.2″ x 3.5″) 6 x Twin Pack (Best paper filter)
- Bestway Flowclear 330gal Filter Pump (Best external pump)
- Lay-Z-Spa Hot Tub Filter Cartridge VI for All Lay-Z-Spa Models – 6 x Twin Pack (12 Filters) (Best multipack paper filter for long term use and to save you money)
- Fineway.® 530gal (2006L)/Hour Clear Filter Water Pump (Most aesthetic pump and for inflatables)
- Achort Replacement Filter for Bestway Filter Cartridge VI for Swimming Pool, Hot Tub, Miami, Vegas, Monaco, Palm Springs, 2 Filters (Best replacement/spare paper filter)
- Intex Krystal Clear 2000 L/hr (530 gals) filter pump (Best high quality, long lasting external pump)
1. Bestway Filter Cartridge I (3.2inch x 3.5inch) 6 x Twin Pack
In our opinion, the bestway filter cartridge is the best paper filter out there, both for effectiveness and reliability. Since it’s Amazon’s choice for hot tub filters and has a four and a half star rating, but is priced at £32 for 6 (bit steep), I wanted to know what the fuss was about. After some playing around, it became clear that this filter is really effective and quite frankly I was really impressed. It justified the price and it’s the one I would suggest for your hot tub. Whilst there isn’t any obvious differences between most paper filters, its effectiveness, robustness and reliability are things that vary and what make this filter better than others.
What I liked about this filter too is that it gives options for the sizes you need, so with the right measurements, you should be able to get a filter which fits your tub nicely. The bog standard filter is a size 1 filter cartridge, the one which is used by most hot tubs, and is suitable for 300 gal/hr pump systems. Either way, just have a good look at the options and see what suits you more.
It’s dead easy to clean too and stays in tact when you give it a wash, which is ideal because a lot of filters start to wear out when you wash them directly. It’s easy to wash off and just as straightforward to put it back in, so this definitely helps! Only problem I would say is because of all the different hot tub brands, many people have accidently ordered the wrong sizes. Whilst you can just refer to your tub manual to check if it will fit, and don’t get me wrong a lot of people have had success with this, you really do need to check if it’s going to be suitable for your tub. Like I said it’s a useful filter that should fit most tubs, but it’s important to check this.
It feels like a robust filter and not like it will fall apart, so it gave me more reassurance once I fitted it that it should last. Other filters feel okay but not as strong as this one, and the integrity of the filter paper is important. Like other filters it’s just plastic, but it’s secure and doesn’t feel cheap, so it’s no surprise it does the job well. So in terms of quality, this filter ticks the boxes.
Overall, I’m confident that this is a really effective and efficient pump which does the job perfectly. It’s reliable too and because it should last you every few weeks, and it’s a pack of 6, this product should last you a good amount of time. It pumps plenty of water through quickly and powerfully and it feels a lot stronger than the others. Compared to the other paper filters in this list, it seems to be far more reliable and the price becomes justified because of this. With this in mind, it would definitely be my first choice and I’m more than happy with it. Just make sure you get the right one!
2. Bestway Flowclear 330gal Filter Pump
Our second spot place is taken by what I consider to be the best external hot tub filter on the market, and I was really pleased with this one to say the least. It’s really good price and actually looks good too, but as a product, it’s really good and it’s reliable too. The main things that stood out were its power (1249L/hour) and its efficiency. It’s clearly got the power it needs and is really good for larger tubs as well as inflatable tubs.
It’s easy to install and all you need to do is connect it up to the tub, and it has the parts included for you to attach it. With some filter paper, it’ll be going for you in no time. What’s great about this filter is that it actually gives you the choice of what power you would want. So, the 1249l/hour is the most basic product, but you can pay more and get a higher power filter if you need. If you have a larger tub, this gives you the flexibility you need for efficient filtering.
On top of this, it just provides a really good amount of power and works effectively without costing an arm and a leg. It might be cheaper, but it isn’t any less reliable or flimsy, so don’t be put off by that. The only issue I might say is that it can be loud at times, but this isn’t a problem if you just leave it to filter when the tub isn’t in use. It fits in nicely with most tubs aesthetically and isn’t an eyesore in the garden, so I am a fan of this one to say the least!
3. Lay-Z-Spa Hot Tub Filter Cartridge VI for All Lay-Z-Spa Models - 6 x Twin Pack (12 Filters)
Next up in the list is another paper option, and actually, it’s pretty on par with our first place spot. Ranked at 5 stars for over 8000 reviews, this seemed to be where you would go for your paper filters, so I was confident it would deliver. Safe to say it does and the reviews aren’t just a load of rubbish, these are great filters and I couldn’t speak any more highly of them.
Just like the filters in spot 1, these are efficient and reliable and they clean really easily. They collect plenty of debris and they feel robust too. So in terms of function they have everything you need, but there are two key things to this product you should know.
Firstly, it’s only £27 for 12 (yes 12) filters which will last you a long time. The only reason it’s not in our first place spot as the best filter is because I class this product as the best for long term use. The reason is because you’ll be replacing your filter often if your hot tub is in a setting where it’s being frequently used throughout the year. So, to save money, that’s why it’s the best spot for this.
Secondly, the reason they’re better than the option 1 filter counterparts is simply because of the quality. Don’t get me wrong these are really good, but like I said, youll go through them quicker and they just quite aren’t as reliable as the filters in option 1. Don’t let this put you off though, the cheap yet efficient nature of this product means this product deserves its spot as second best paper filter.
4. Fineway.® 530gal (2006L)/Hour Clear Filter Water Pump
Next up is the most expensive filter in our list, but because it’s an electric external filter, it’s easily the one with the most power out of them all. It pumps 2006l/hour and is ideal for tanks up to 13000 litres, so it’s definitely for you if you have a large hot tub and if you’re not worried about splashing out.
Compared to option one’s highest power product, the fact it’s more expensive and is from a high quality brand (Fineway does some really good garden stuff that’s worth checking out!), I’m confident in saying that this will last you longer. This pumps the tub quieter and with ease, and since it’s designed for larger tubs and heavier water bodies, it works perfectly on both inflatable and hardware tubs alike. Both are great, but this simply has more power and is more expensive, so it’s really a case of getting what you pay for.
That in mind, the reason it’s not in first place is because you don’t necessarily need this pump if you have standard/smaller scale hot tubs. It’s a bit much and option one will work perfectly for you. Since this is pretty much designed for pool use too, it’s only worthwhile on tubs which are over 10000 gallons I would say. It might last you a bit longer than option one, but this isn’t the most important aspect in external electric tub filters because they aren’t switched on all the time.
5. Achort Replacement Filter for Bestway Filter Cartridge VI, 2 Filters
Straight off the bat this paper filter isn’t the best in terms of function and efficiency, which I feel is the main thing to get out there, but it does do its job and it’s the most reliable replacement/cheaper option there is. Since it’s only a 2 pack, I would only get this if I needed emergency replacement filters or if I don’t use the tub much, as I wouldn’t say it’s ideal for long term use.
That shouldn’t put you off though, because like I said it still gets the job done, it’s just not quite as good quality as the filters above. It is really good at getting dirt and dust out etc, but it doesn’t end up with as much collected waste as the other filters, so I can assume that it isn’t 100% efficient in getting all the smaller bits of dirt out. This isn’t the end of the world, but it does mean the quality isn’t the best.
That in mind, it makes it the perfect filter for infrequent or unoften tub use, so if it’s only out a few times a year or a few times in the summer then this filter is fine. It will only fit certain tubs too, but what I liked about it is that whilst it performed reasonably well (not better than 1 and 3 though), it seemed pretty robust and like it would last. So, since it will probably last and does an ok/reasonable job at filtering, and for a good price, I’m confident this would be the one for me if I used the tub less than I do and if I quickly needed a replacement.
6. Intex Krystal Clear 2000 L/hr (530 gals) filter pump
In our final spot is another external electric filter pump system, and it’s up there with the other two in this list to say the least, but it just doesn’t quite top them for a couple of reasons. This filter pumps 2000l/hour and is actually designed mostly for swimming pools, but its pumping power and reliability make it perfect for hot tubs. I wouldn’t recommend this on smaller hot tubs, but it will be fine with larger ones.
It comes with the two hoses and all the fittings, so you have everything you need. I am a fan of this pump and it did feel like it had the power to it, but it doesn’t look the nicest compared to the other options and I know that’s picky, but hot tubs can be quite the aesthetic to the garden and the pump becomes part of it, so it needs to look semi-decent. On top of this it’s the most expensive one, which yes indicates reliability and reassures me it will last a bit longer, but this isn’t overly important here since the other pumps were cheaper and still as reliable.
So, it’s a solid pump and will work great with large tubs, but it’s expensive and doesn’t look great, so that’s why I don’t rank it as highly as the others in this list. I’d still recommend it just as much though, especially for larger tubs, as it does deliver on the power and filtering effectiveness front to say the least.
As already mentioned, hot tub filters are typically external (as a pump system) or as just paper filters, but there are a few things you need to know about both before you buy. On top of this there are a few key things to look for when it comes to hot tub filters, but don’t worry, it’s covered below.
Paper filters what you need to know an example uses
Paper filters are cheaper than external filters and chances are they will fit directly into your hot tub giving the easiest average test case and example use. However, most external filters also require a paper filter in them, so the two types of filter typically go hand in hand. They come in all different sizes and specifications which of course depend on your hot tub, so check the specs of your tub before buying. If you’re not sure on this though, all you need to do is grab a tape measure and take some accurate measurements of the filter slot. Compare this with the specifications of filter products online and buy the appropriate product. If it’s wrong, the worst case scenario is you send it back and order a different size, but this would only happen if you don’t know your tub specs.
Filters should be made from what feels like a robust/sturdy plastic which doesn’t feel flimsy at all. The paper should be thin but not feel like normal paper, and once dirt gets collected, paper filters should be easy to wash and clean. You’ll notice they wear off after a short time anyway due to the nature of their function, but they still need to be of a certain quality. It’s also good to look for multi packs of paper filters to save money.
External filters- what you need to know and potential problems
When it comes to external filters, you’re pretty much talking about electric pump systems that are used on larger tubs or on inflatable tubs. There’s quite a variety available, and most of them are typically used for pool use as well as hot tubs, so you can tell they’ll be powerful. They range from £30-70 (good value ones anyway) and at this price you should be able to get yourself a long lasting pump that can pump and filter around 2000L (depending on the model) of water per hour. This is plenty for your standard tub but if you have a tub around 10000-13000 gallons, then you might want something more powerful. You need to be careful though as the problem with the lower quality filters is quick failure or seizure of the motor.
Since most of you will have inflatable tubs, a filter pump is exactly what you’ll need and you’ll also need the right paper filter to go alongside it. They should come with pipes and all the fittings to stop you having to buy them separately after. I find with external pumps it’s important to have it looking good too, because the hot tub is a genuinely nice feature in any garden and is most commonly part of the garden aesthetic itself, so why have a nasty looking pump?
They can also be quite loud, so it’s worth reading reviews for this. If you don’t use the tub often this isn’t much of an issue because you can just leave it on when you’re not in use. If you do use it often though, try getting a quieter filter pump.
In terms of power, 1800-2400l/hour is all you need for most tubs and 230-250 volts will do too. With these specs and a nice looking filter pump, you’re good to go.
The thing to consider with hot tub filter products, mostly paper, is that they come in different sized multipacks. This makes a huge difference to the value of the product and which one you buy for how often you use the tub. For example, if you use it often, you’ll want to buy a product such as number 3 because of its good value for money and because it includes plenty of filters. On the other hand, if you just need a spare or if you use your tub sparingly, paper filters such as option 1 are absolutely fine.
Since filtering is quite a job, you need something that will last. Paper filters won’t last too long and you’ll typically need to replace them after a couple of weeks, but the better quality, the less you will use and the less you’ll have to spend. For external pumps, more expensive ones will typically last longer, but as long as they have a reasonable amount of power and you’re not overdoing it (for example a 1800l/hour in a 13000 gallon tub is working it too much) then you should be fine. Check the reviews too for any issues about reliability/breakage.
Now you have an idea of what hot tub filters are/used for alongside our suggested products, we’re hoping you will be able to pick out the right one for you…just remember to pick the right size!