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.