Arthritis

Every month I get inspired to write more and more because of the silly stuff I hear about sales pitches from customers.  Here is some of it.

"Only our spas are rated for use by the Arthritis Foundation."   This was told to me by a woman with arthritis who was about to buy one of their spas, based upon the salesman's false implications.
First of all, arthritis is a painful disease.  Not fun at all.   I don't understand why some sales guy would play on a person's pain like that!

It has been my understanding from talking with sufferers of this affliction that the water jets may not be the best therapy for inflamed joints.   In hospitals, they use bubble therapy most of the time, because it doesn't apply pressure to an already sore joint.  Or they use a whirlpool of low pressure water.

The spa this sales guy was trying to sell has no air bubble jets at all.   The woman would have to just sit in still water in order to not have jets on her sore joints.
Or she would have to sit in a seat without the jets turned on and let the other jets swirl some water around.

I would like to see all spa manufactures not use  any medical ailments as part of their sales propaganda.   It is a low blow to the industry to imply that only their spas are good for arthritis!  Let me give a clue here:

All spas are good for arthritis!   Blower therapy is preferred, because it doesn't apply pressure to inflamed joints.

When I was taught how to plumb a spa, we used primer and glue to make the joints not leak.   I have seen loose flex PVC, just hanging there is spas over 16 years old, right at the pump where the pressure is the greatest.   Please don't believe that one!

Actually the best way to keep the spa from leaking for the longest time is the use solid PVC  as much as possible.

100% Filtration

I never seem to get tired of explaining this one,   It is written in my book and now here it is on the web for your benefit.
There is no such thing as 100% filtration!   There! I've got it off my chest.  Now I feel better.
If there was 100% filtration, you would have all of the water removed, pumped out,  and then filtered as it would be pumped  back in, so that 100% of the water was forced through a filter as it returned to the spa.   I supposed if you wanted 100% filtration, you could buy a water tank to hold all of the spa water.

Whenever the term 100% filtration and a tiny 7 GPM circulation pump are used in a brochure, it becomes consumer fraud, or extremely close to consumer fraud.  This is only one of the several reasons why the tiny circ pump is stupid engineering.

The best filtration available today is running a modern two speed pump on low speed 40 to 50 GPM, using a check valve on the open suction in the bottom that closes when the pump is on low speed.  When the pump is filtering with this configuration, a lot of water is moved quickly into the filter.
Filtering is a long process, because as the filtered water returns into the spa vessel, it is mixed with the other water containing debris.   As the water circulates, gradually more and more particles of debris are filtered out.  We have found that six to eight hours per day is required to get good clear water with almost all the debris filtered out.

The common method of so called "100%" filtration is to completely block the suction of the spa pump with a filter, and not allow any water to go into the pump that is not passed through the filter (no check valve).   There are a couple of engineering problems with this.  1/   The jets get weaker as the filters get dirty and clogs up.   The only time the jets have full pressure is with brand new filters.   2/  The worst thing to do with a pump is to block the suctions and give the pump more work to do with less felt jet pressure.   This increases electrical usage and your electric bill.

I have had customers bring in filters that are caved in on the sides from the pump trying to get water.   The first time I saw one of these filters,  I knew there was something wrong with this filter system, so I started my investigation.
I talked the other day with an expert on water pumps.  He is an engineer from a different field, that uses the same types of pumps that spas do.  He told me that when you apply back pressure to a spa pump, it is no where near as dumb as holding back the water on the suction side.   The amperage goes up if the suction is restricted.
I have seen pumps burn out from having too small of a suction or filter restricted suctions.   I have seen this in two different spa brands, both with so called "100%" filtration.
In our spas we allow water to be drawn in from the bottom and the top.  If there is any restriction in the filter, the water has another path, and does not cause the pump to overheat, or the jet pressure to drop.   If you know of a better way, be sure to let me know!

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