When customers come into our store and are regular shoppers with no spa experience, they have no idea what it is they are buying. They are literally at the mercy of sales scripts that are designed to move products, not to educate the consumer.
I have asked many of them: " How much do you know about spas?"; and the answer is usually: "Not much.".
sales guy tells a shopper that their spas have 100%
filtering and that it is the best, when it is actually a
very poor design, the shoppers do not have a chance at
getting proper advice from the sales person. The spa sales
person, who by the way, is just as ignorant about spas
as the shopper, in most cases. Sales people are not normally
engineers or scientists. They are just clearly reading a
script they memorized.
sales pitch implies that a spa with a no bypass filtering
system works better than a filter design with a lot more
water moving into the filter and a lot more agitation, that
is a savvy sales technique. It is "word smithing" to the
highest degree of the art of making a poor design sound
good. In sales the norm is if you have a weakness you
know is a flaw, you must still make it sound good if you
want to pay your house rent or mortgage. This is just
how it is in a money driven society for the most part.
A "no bypass" filtering system means that the end of the pipe leading to the inlet on the pump has a filter on it and only a filter on it and in the case of today's spas it may haver two filters on it. That means that all the water entering the pump is going through a filter.
nothing wrong with this concept, except that the company
that uses it, is not following any engineering standards for
the size of the filters in relation to the size of the
pumps. The pumps in this brand of hot tub, can easily
overdraw the filter, causing way too much vacuum on the
suction side of the pump. The way to compensate for
that is to put too large of a motor on the pump, because if
they used the correct size that other companies use, the
motors would quickly burn out.
2005 forward they started putting high flow screens in
the filter housing so they can further violate the ANSI and
UL by having a super high volume pass through one area of
the tub. They did this because the competition make better
therapy machines with high HP and normal ANSI engineered
bypass filtering. The largest spa company has used
this sales pitch for too long. So, they have all their
sales people believing this sales pitch. If they
changed the design, the sales pitch would not work any more.
They would, thus, be admitting that for 40 years they have
imply to people who don't know anything about spa filtering,
victimizing their own customers, that "all the water
is filtered all the time." That is a direct quote from
advertising. It does not work the way
advertising people make it out to sound. The only way to
filter all the water all the time is not available on this
planet. You cannot instantaneously have all the water in the
filter. It is an unethical approach to a relationship
with other humans.
REALITY OF FILTERING
The reality on how ALL filtering works is that it is a progressive reduction of particles of debris over a period of time. It involves both drawing in the water, passing it through a filter, then spraying it out and mixing the filtered water with the dirty water. With each passage through the filter, the particles gradually collect on the filter fiber. The filters extract debris, but the filtered water is then sprayed back into the dirty water. This is similar to having a bucket of dirty water scoop out a cup of dirty water and you pour in a cup of clean water. Very gradually by this process the water become clear. That is why over 10,000 gallons of water needs to pass through the filter in a 250 gallon spa in order to remove enough debris to have real water clarity.
The other part of the equation is the nominal size of the particles being captured. The smallest being 10 microns and the largest 50 microns. This is designed to take out pretty much all the visible debris. The rest has to be taken care of by chemicals that destroy organic compounds. If you have poor filtering as in the series of tiny circ drawings below, you will use more chemicals or ozone to remove organic compounds. If the filtering is inadequate, then use more chemicals to make up for it.
words, the filtering is limited by the size of the porosity
of the fiber. It's also limited by the amount of water
passing through the filter each day and the degree of
agitation. It does not matter so much if it is a
"bypass system" or a "no bypass" system as long as over
10,000 gallons pass through the actual filter fiber in the
cartridge daily. If the spa is used more you need
more filtering. Filtering capacity is totally
determined by the amount of debris per gallon of water.
More use = more filtering. (That is why we
recommend more filtering, instead of less, because Haven
spas are used almost every day by our customers for stress
and pain reduction. These are real therapy pumps.)
Here is a drawing depicting exactly what I was explaining on the progressive reduction of particles. The top is before filtering and the bottom is after 8 hours. This is using a much larger pump and moving 40 GPM (gallons per minute) or 2400 GPH (gallons per hour) for 8 hours for a total of 19,200 gallons per day. This is very effective filtering because the water is actually forced to move by the strength of the jets. This makes the debris reach the filter and be taken out of the vessel. These illustrations only depict filtering of debris and do not allow for any ozone, chlorine, bromine or shock.
Once again it doesn't matter if there is bypass or not. It matters how the water is filtered. To imply that all the water is filtered in a tiny percent bypass system is wrong! In order to have filtering you need agitation, water movement, and gallons per hour passing through the filter media that is equal to or greater than the volume of the spa.
All the water is filtered the same in a bypass system where 19,000 gallons pass through the filter, compared to a no bypass filtering system that filters 19,000 passing through the filter. The filtering is the same.
It is the water that passes through the filter that counts and if the water is agitated enough to push the debris from all corners of the spa into the filter.
Consider the following drawings depicting my experience with the tiny circulation pump (actual testing on this companies products). There is an outlet at the bottom of the tub that bubbles up a little water at a time. In this "no bypass" system a lot of water gets "bypassed" because it stays for a long time in the extremely slow moving areas. In this method the water near the filter and towards the filter is where the bubbles are heading.
There is no propulsion of a water jet to make the water churn and get the debris on the back side and back corners.
experience is when you leave the spa to run on the tiny circ
pump it takes many days for all the water to make it to the
filter, if you don't supplement the filtering with a jet
pump. I did this test several times with a spa used with
only two people. After four days the water started to clear
up. It had proper amounts of sanitizer so that that was not
part of the experiment.
When I hear the sales pitch coming out of a sales person's mouth about 100% filtering all the time, it really makes me wonder about the ethics or intelligence of the company who would be telling people such nonsense. Most large spas using the tiny "5000" pump illustration below are way under filtered if the spa is used by two people daily and the customer do complain about it. This illustration shows that it takes two days to get the same amount of filtering as in the properly designed illustration above.
drawings are based upon two days of filtering with the tiny
pump only. The top drawing is the beginning of the time
period, right after the jet pumps turn off on a spa that is
used by four people. The last drawing is the finish of 48