Filtration systems

Filtration systems

I’ve gotten a lot of questions about this from you guys so I made this video to answer them.

The Filter Wars

Back in the 80’s the industry had a bit of a marketing war over filters, mostly playing off the misconception that twice as many filters or twice as large made the tub twice as clean which sounds great! we love our hot tub to be clean who wouldn’t? This kind of marketing really sold tubs back then, it got to the point where people were sticking something insane like 5 filters in a single tub and calling it 5 times cleaner, other than a few brands the hype didn’t keep up forever, most manufacturers went back to a single 50 square foot filter which is really all you need.

What filter systems keep your hot tub the cleanest

Why is a 50 square foot filter all you need? There is some serious misunderstanding about what filters actually do, they exist to deal with debris, all the loose stuff that we carry into our hot tub and even on the lowest end ones in the market they get this right. Filters are not meant to deal with bacteria, viruses or anything else, (unless they have some other add on like zinc ion) That is the job of your water chemistry. So for debris clean is clean, past a point more filtration isn’t going to pick up anything that hasn’t been caught by smaller filters.

Bypass systems are just as effective as those ones that talk about non-bypass systems filtering every drop of water, the filtered water still goes right back and mixes with the rest of the tub, all they are doing is trying to make it sound good. Eventually all that water gets filtered no matter the system. Water flow determines the rate of cleaning far more than anything else, so those tiny circulation pumps with four or five filters are a lot slower than a high flow filtration system with a smaller filter.

Suction side VS Pressure side filter systems

A lot of people try to twist this to make it sound like pressure systems are better, and hey, the word certainly has more buzz and appeal. They filter with pressure! that has to be better!
All it really means is which side of the pump the filter is on, the water flow is the exact same. It is actually better to be doing suction side, since the filtration happens before the water gets to your pump there is less debris that it is exposed to.  The difference isn’t significant though, this should not be a major factor in which tub you buy and if someone tries to tell you it is they are taking you for a ride.

For the most part you should ignore filters when trying to buy, anyone who is saying their system is far superior is just trying to hook you in with smoke and mirrors marketing.



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Live in Fort Worth texas wondering about maax or vita spas, they have the parameter insulation like PDC spas, comments!

Hi Scott The Vita I looked at used a fairly inexpensive lower R-value insulation, did not clamp the plumbing lines and had a less expensive cradle supported shell… Not a nightmare, but not top quality either. Maax is a company that makes everything from doors to tubs and I never trust the jack-of-all-trades type operation. They’re no doubt great with acrylic but there is far more that goes into spa than the acrylic and steel frames always make me cringe because I’ve seen so many rust and rot over the years. PDC is the one to go for out of… Read more »

Hi there,
I’ve had a few one spa dealers tell me that ‘more filtration is better’, ie. A spa with 2 x filters (giving 100 sqft of filtration surface) is going to have cleaner water than a tub of the same size with 1 x 30sqft filter. Do you know if there any truth to this? Does the Spa with 1 smaller filter have to work longer / harder to filter the same amount of water than the spa with 3 x the ‘filtration area’?

Foret the filtration bullshit all spas even the cheap Chinese Crapo from the mass merchants filter the water really well.

Hello where do i buy a suction filter for hot tub?

do you mean the whole assembly? or just the filter cartridge?

Hello the whole assembly,and possibly pump for bubbles , see i am making my own hot tub wood fired, self sustainable, but i don’t want to dump after every use, i like to clean disinfect water properly, try to use water long as i may safely.

Any hot tub dealer should have access to those parts. Just tell them you need a skimmer assembly

Hi there..our family of 4 is now looking at the master spa 7.5 because of locating your website! Your website helped us navigate the murky hot tub business (we almost bought a HotSprings highlife series, 5 seater, salt water system for over $1500.00 CAD)! But now we have been educated and focused on the master spas! I liked your review on using the Spa Marvel enzymes to treat hot tub water..we are completely new to hot tubs and water maintenance..we like to keep things simple! Master spas is trying to get us to upgrade to their Mast3rPur™ Water Management System… Read more »

Hi Mark, With the standard Eco-Pur cartridge in the Master and using Spa Marvel you will be at drinking water levels of chlorine so there is absolutely no need for anything beyond those. The beauty of Eco-Pur and Spa Marvel is that there is nothing to wear out or break. Mast3rPur and Quietflo are simply a 24 hour circulation pump combined with a UV light purification system. I am not a fan of circ pumps in the Master series because I’ve seen too many issues with them and there’s no need for UV with Spa Marvel so my advice would… Read more »

Thanks Bill for the quick reply..I’m assuming we will still have to check PH and Chlorine levels sporadically? Will I still have to use these chemicals in small amounts to treat the water? If so, do you recommend any testing and chemical products for this purpose?

we just want to start our brand new hottub on the right path to give us the least water problems down the road..



I have owned a Hot Springs Grandee and a Dimension One Diplomat. After 28 years of service with the Grandee and 16 years with the Diplomat, I feel that the Grande water quality was always better. Not sure why but I did attribute it to the 5 filters vs 2. I am now in the market for my third hot tub and seeing that I haven’t purchased one in 16 years, have started doing more research. I have been listening to most of your videos to get your perspective. Just curious about one thing. You say that you like suction… Read more »

Hi joseph My stance on filtration is more along the lines of its really not a huge issue either way. also water quality does not have that much to do with filtration it has way more to do with sanitation. all filters do is take the debris out of the tub and frankly, even the cheapo tubs filter effectively. I have never seen any tub with lots of debris floating around. I have no issue with the hot springs way of filtering either but its more of their typical marketing spin and bullshit that it is any real advantage. The… Read more »

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