Filtering experiment, test results are in...

[wetone]

There’s been a number of debates about filtering and circ pumps so out of curiosity we did an experiment with two different manufactures tubs side by side in our store. (we sell both brands)
The store is on well water, iron and heavy sulphur, water is brown with a heavy rotten egg smell, can barley see the bottom of a fresh filled tub.

Both tubs around 400 gallons. Fill temp 55F
Tub #1, with a 24-hour circ pump and 24 ozone. Pump 1 set to filter 3 hours every 12 hours. 2 – 75 sq/ft filters.
Tub #2, no circ pump, pump 1 set to filter 3 hours every 12 hours with ozone, 1 – 75 sq/ft filter.

Both tubs filled up and started at same time, same start up chemicals in both, they both ran through the 3-hour filter cycle on start up.

Both tubs were set to heat to 80.
On tub #1 the main pump turned of after the filter cycle, leaving the circ pump to heat the water.
Tub #2’s main pump continued to run on low speed till it reached 80 degrees then turn off, total run time 4 hours 10 minutes including the 3 hour filter time.

The test results after 4 hours and 10 minutes, tub #2 water was crystal clear, #1 water was clean (brown color gone) but not clear.

24 hours later, tub #1 water was still not 100% cleared up, still a bit hazy.

To make sure that something wasn’t missed on tub #1, we did the entire test over with 2 different models this time, the results, exactly the same as first round.

The results are the opposite of what we expected.

The models used for this experiment were, #1, Dimension One Chairman II, #2, Coleman X80 Premium.

The Dimension One with the 24 hour ozone and circ pump is supposed to clean up quicker then the Coleman with no circ pump and just ozone during filter cycles, why the difference?

Why does one tub clean up so much faster then the other?

Any ideas?

John

[Chas]

The results are the opposite of what we expected. Why does one tub clean up so much faster then the other?

Any ideas? John

John, this is very interesting, thanks for taking time. To a certain extent, you are comparing apples to oranges: one of your tubs is running a large jet pump on low speed for four hours, while the other one got it's initial 3 hour run but then switched to the low-flow circ pump.

I don't know the exact plumbing schematics of these two tubs, but you also have one vs. two filters, and we have no way of knowing how clean the filters were to start with.

Keep in mind that tubs with bypass arrangements (and this is where the arguing usually starts) are VERY sensitive to the condition of the filter. If the filter is coated with dirt, or even a thin film of oil, the water will simply enter the other opening. As the filter gets dirtier, there is less filtering going on.

I would love to have you put a no-bypass tub next to a bypass tub and run the jets for the same length of time with your brown water.

By the way: does your water run cleaner after it has been running awhile? I'm asking about the supply water: do you get more crud at first and then less after it has been running for awhile? This could also affect the amount of stuff in each tub. The one you fill first may have more than the second one.

[Mendocino101]

The answer is simple Hi Flow filtering or more water turnover in  shorter time or less water turn over but filtering 24 hours consistently .....if you are talking about your "standard"  circ pump around 6-8 GPM  you will turn the water over in that 400 gallon tub about 24 times in a day but with the Hi Flow system you will turn it over about 75 times in the day....some people like the idea of 24 hours of ozone....I know our water is always crystal clear on our floor we use a Hi Flow system.....but I am sure the both work fine.

[Mendocino101]

I don't know perhaps I should not comment here......BUT.....there are many good folks on this board who believe as we should in the product we represent....and while there are several makers who over the years have earned their good reputions..... still among those makers some will choose to build a product that is different from the others....and one can endlessly argue why one way is better than the other but for both sides there are real advantages and some disadvantages to each way.....at the end of the day all your better makers will give you a spa that will keep your water hot, clean and do so at a reasonable cost to run each month and should you have a problem they will stand behind your spa.....Forgive me if this does not belong in this thread but after reading Chas's post it just made me think of the differences and believes of what is the better way and remind me that there are several ways that work.

[hymbaw]

Try the same experiment with water already at desired temp. The only reason you got the extra filtration in the coleman is because it was heating water.

So if you are saying that no circ pump will clean the water faster at start up, I agree. What about the rest of the year?

I would love to see the experiment done with a tub with a "real" circ pump (35 gpm). A Sundance for instance!

[spahappy]

John I've had similar results between the Coleman 471 and the Jacuzzi 355 that we have on our floor as well. Did you use a first filter on the Coleman?

I've also noticed that the Coleman will heat up on a fresh fill faster than the Jacuzzi due to the high flow jet pump connected to the heater vs a circ. pump.

To me this isn't a big issue as both spas will run about the same to heat once they're up to temp and running under similar situations.

Good information, thanks for sharing.

Spahappy

[Mendocino101]

Try the same experiment with water already at desired temp. The only reason you got the extra filtration in the coleman is because it was heating water.

So if you are saying that no circ pump will clean the water faster at start up, I agree. What about the rest of the year?

I would love to see the experiment done with a tub with a "real" circ pump (35 gpm). A Sundance for instance!

lol....wow its good to look at the diffrences... that real circ pump on the Sundance are they also still running the larger pumps during the day in addition to that real pump and if so WHY? that is is something that is newer right? I understand that it will not be around long as with the current system there is no chance of it passing the energy standards that are going to be required here in the very near future.

[wetone]

I would love to see the experiment done with a tub with a "real" circ pump (35 gpm). A Sundance for instance!

Will try this as soon as the Sundance line arrives at the new store coming up.. late July early Aug if all goes well, will post the results

[wetone]

no way of knowing how clean the filters were to start with.

New filters in both...

By the way: does your water run cleaner after it has been running awhile?
 

Can run it 2 min or 8 hours no change.

[DPS]

It is the turnover ratio that matters.  The higher turnover ratio spa will have a quicker clean-up time.  If a tub can have a high turnover ratio AND a low operating cost - that would be the kind of tub to get.

[In Canada eh]

Isn't everybody missing the other meaning behind the circ pump, energy effiecency.  While it is true that the larger pump will clean up the water faster the true test is to compare results of water chemical and energy used over a longer period of time .  The results should favour the circ pump.  The two diferent methods

1- a large amount of water over 2hour filter cycle

2-a small amount of water over 24 hours

Both will probally equal the same amount of water filtered

[tony]

lol....wow its good to look at the diffrences... that real circ pump on the Sundance are they also still running the larger pumps during the day in addition to that real pump and if so WHY? that is is something that is newer right? I understand that it will not be around long as with the current system there is no chance of it passing the energy standards that are going to be required here in the very near future.

The high flow circ pumps on the upper end Sundance spas do all the filtering.  The main pumps are for therapy only.  This differs from the older style Sundance system that used a low flow circ pump with the two speed therapy pump number one that also filtered.

[Mendocino101]

The high flow circ pumps on the upper end Sundance spas do all the filtering.  The main pumps are for therapy only.  This differs from the older style Sundance system that used a low flow circ pump with the two speed therapy pump number one that also filtered.

That was my question and it has been my understanding that they do still run the bigger pumps....What ever the answer is I think all makers are going to being tweaking their system somewhat to meet the new energy standards...I know most of Marquis units have passed what the anticipated requirements will be but a few models need some minor adjustments.

[spahappy]

The high flow circ pumps on the upper end Sundance spas do all the filtering.  The main pumps are for therapy only.  This differs from the older style Sundance system that used a low flow circ pump with the two speed therapy pump number one that also filtered.

So you're saying that the  jet pumps don't come on at all during filtration... not even when the spa defaults back to factory programing?

[Mendocino101]

So you're saying that the  jet pumps don't come on at all during filtration... not even when the spa defaults back to factory programing?

That was my understanding that they do still run the larger pumps...