Opinions on filtration systems

[Steve]

What is your opinion on pressurized canisters compared to top load skimmers?    thx...

Steve

[Spa_Tech]

When I make recommendation to my customers about this topic, I think of three words.


Ease of maintenance.

While pressurized filtration may net better overall filtration results, it is simply easier for consumers to maintain a top loading non pressurized system. With a simpler process, it increases the likelihood filter cleaning will get done.

There have been a number of occasions when Ive repaired a spa with pressurized or 'in-line' filter systems where the filter cartridge hadnt seen the light of day in years. I even had the response of... "Gee, I didnt even know that was there...."

[Spatech_tuo]

Ease of maintenance.

Agree completely. A top loading filter with a skimmer works well and you stand a better chance of the customer actually cleaning it as they're supposed to. I got a call from a guy who bought 2½ months ago who swore he was following the water maintenane instructions I gave him but was having a tough time of late. The instructions clearly tell him to clean the filter monthly (and rinse it in between if necessary due to heavy use). At the end of the instructions it repeats that filter cleaning cannot be neglected. When I asked him when he last cleaned his filter his response was "oops, I haven't yet". If you add in a filter system that isn't as convenient you'll loose even more people. You could agrue that a slacker will fail either way and a thorough person follows through either way but I definitely disagree. The more you can "dummy proof" any consumer product or in this case make it more user friendly, the more you stand the chance of the consumer operating it properly.

[Steve]

Can one say that a pressurized system definitely filters better for sure? Given identical spas and usage, will the pressurized system perform better over a longer period of time? Does the filter itself make a huge difference?

What is the % of companies using pressurized IYO?
Steve

[Chas]

There have been a number of occasions when I've repaired a spa with pressurized or 'in-line' filter systems where the filter cartridge hadn't seen the light of day in years. I even had the response of... "Gee, I didnt even know that was there...."

Yup - me too. And when a pressure filter gets plugged the pressure goes up to whatever the pump can put out, and you have the possibility of the lid going balistic. There is no such chance with a top-load. Some in-line filters have a bypass that automatically opens to keep this from happening - but if that's the case, then you may have little or no filtration once the filter gets a bit of dirt or oil on it. Also, many of these systems are designed right from the start to open a bypass when the pump in on high, and close that bypass when the pump is on low. That means that you actually ONLY have filtration on low - and very little or none when the jets are on. This is the oposite of what is generally needed.

Also, most pressure filters are hard to open and close, and if you don't keep a spare o-ring on hand, you may open it only to find that you now can't get it closed again without a trip to the dealer - who had better be open right now....

[autoplay]

I looked at the hydropool spa dealer here in Sarasota,and initially I was impressed by the pressurized filter apparatus. Then thinking about it,it seemed like something more to maintain,and possibly leak etc.

I was impressed with their insulation method,from a visual perspective. If I recall,they used a thin layer of foam on the shell....and used reflective insulation on the walls,which in essence,gives you an air barrier(which is what you want for optimal insulation purposes).

Back to the football game

[Vinny]

One of the tubs I'm looking at is Emerald and they use a pressurized system.  I didn't look at it as a positive or negative - just a different way to filter.

As a consumer and not at all in the hot tub industry, it may be true that it's easier to maintain a non pressurized system but the user or maintainer of the tub should properly maintain the tub. I believe the majority of people buy something (anything) and don't properly understand the work involved. I own a pool and to me it's not too much trouble BUT I here it all the time how hard it is to maintain a pool.

I work in the medical repair industry and people will destroy things IF it's not brought to their attention. As a tech, I bring it to their attention by hitting their pocket book when it's appropriate. (Someone drops something for the second or more time).  For those of you who have to "fix" a dirty filter, maybe a reminder that this call was free and the next time it'll be billed at $( fill in) per hour travel and labor because of operator abuse and operator error.

Maybe as dealers, you can "include" in the price a second set of filters, then the people would have a constant reminder of that round white thingy needs to be changed.

[stuart]

OK, I was going to stay out of this one but....

If filter system is "pressurized" then that means it would have to be on the Pressure side of the pump correct? If that’s true then wouldn't all of the hair, lint debris and bacteria pass directly through the pump? Ever pulled a pump apart with all of that nasty crap in it?

Wouldn't you want to stop as much of that and all of the oil before it comes into contact with any hard "permanent" plumbing parts?

Consequently, if it is not on the pressure side would it be as effective in concept as if it were a "pressure" filter

Doesn't that closed up canister act as bacteria pit? Back to Chas's comment. How can the filter and canister hold up to real pressure considering the natural "blockage" it has to create? How could it skim the oils well (oh yeah, the pump impellor is collecting those for us!).

Steve,
Just a guess but, I would say less than 10% of the manufactures with any credibility still use that type of system.

[Vinny]

Stuart,

I'm not trying to be a smart  a** here but I do have some questions.

I look at pressurized filters the same as pool filters. Why would a pool filter be different than a pressurized tub filter. I know about the vast quantity of water in a pool vs tub but what's the difference in how they operate?

If your sanitizing the tub correctly it shouldn't matter which comes first - the filter or the pump in the case of bacteria. And the pressurizing vessel for the filter should also be disinfected if the sanitizer levels (chlorine or bromine) are correct along with a weekly shock (at least with chlorine). I do assume this is happening in my pool filter.  Is this a correct assumption?

As far as body oils - I've read there's a product called swirl away that cleans the pipes of the gunk in it. I would imagine that tub maintenance means exactly that and using a product to clean what can't be seen makes sense. If it works as people have stated (apparently great), why not use it on the tub before emptying it to clean the pipes every 3-4 months? Wouldn't this work at getting the oils out of the pump and pipes?

Now to the question of pressure in the pressurized canister. I constantly look at my pool filter's pressure and the filter media (D.E.) is changed on a monthly basis. If a cartridge filter is changed or cleaned every 1 or 2 weeks then that should be a non-issue for the pressure to build up to a critical level.  Am I missing something?

My asking these questions is based the assumption that someone actually maintains their tub properly - not someone who fills it up and forgets that something has to be done.

Thanks,

Vinny

[Shut_Down_Stranger]

technically speaking.... from a filter person.

The suction filters operate under differential pressure of up to 15 psi. in reality, its effective limit is about 10-12 psi.

Pressure filters can operate at higher differential pressure, (up to 35 psi or more) so can be smaller, but once you get above a certain pressure you begin to restrict flow and that is not a good thing. Filters become self limiting in terms of flow and differential pressure because of the dynamics of the centrifugal pump.

Filtration efficiency is determined by the filter media. Most spa filters from what I have seen or estimate are in the range of 20 to 40 microns, not really tight enough to significantly reduce turbidity in water, that is the job of the disinfectant. However, the tighter the filter media the more the filter will remove and the clearer the water will become.  

Most pressure filters rely on the filter getting a bit dirty in order to improve filtration effieiceny. The filter adage is that "a dirty filter filters better (more efficiently) than a clean filter" is true". That is great if you are going to continuously operate the pump, not so good for a spa, where the pump only operates intermittently. Once the pump is stopped, the trapped dirt falls to the bottom of the filter.  

Effective filtration, suction or pressure, is all about surface area. The pleated filter arrangement provides a lot of square footage and will generally not clog. So the multiple filter arrangment are generally better. To some degree filtration effeiciency can be affected by the flow, so the more area the higher the filters efficiency.

We recently looked a the LA Spas filter arrangement which had been converted to a suction bag type filter. This type does not have the surface area. We wound up passing on the type although they stated "a back-retrofit would be available "soon."  

One of the more innovate concepts is that sundance has a fine filter on the small recir pump, that may offer some advantage in clearing up a cloudy spa.

Bottom line - for continuous use a pressure filter would probably be better, but for spas, whos pumps operate only when we are in them, the suction style is preferable and simpler to maintain.

No filter will effectivley remove oils and greases, sorry, that is the disinfectants job.      

[Vinny]

Thanks for the info!

[Spa_Tech]

I work in the medical repair industry and people will destroy things IF it's not brought to their attention. As a tech, I bring it to their attention by hitting their pocket book when it's appropriate. (Someone drops something for the second or more time).  For those of you who have to "fix" a dirty filter, maybe a reminder that this call was free and the next time it'll be billed at $( fill in) per hour travel and labor because of operator abuse and operator error.

I dont think many service techs really can afford to comp a service call on a nuisance or neglect call. Before scheduling a service call, I have a list of troubleshooting questions I ask so that I'm not going to a customers house simply to clean their filters or reset a high limit.

If ultimately, the customer gives me inaccurate information, and I do end up cleaning their filters or recommend their replacement and no other repair is needed I still charge them for the service call- The reason is simple- If I werent here cleaning their dirty filters I would be elsewhere fixing 'real' problems and making the same or better money.

[Vinny]

"I dont think many service techs really can afford to comp a service call on a nuisance or neglect call. Before scheduling a service call, I have a list of troubleshooting questions I ask so that I'm not going to a customers house simply to clean their filters or reset a high limit. "


I was assuming that these calls would be covered under the tub's warranty (1st one of this type). Hopefully this problem is a newbie problem and not an ongoing problem.

[Spa_Tech]

I was assuming that these calls would be covered under the tub's warranty (1st one of this type). Hopefully this problem is a newbie problem and not an ongoing problem.

Vinny, to my knowledge, there isnt a spa warranty out there that covers neglect, misuse, or abuse such as dirty, clogged, or calcified filters. This is a spa consumer responsibility and is specifically detatailed in many warranties...If you dont follow intructions outlined in the manufacturers spa owners manuals, you will probably be charged if a service tech comes to clean your filters, reguardless of your warranty status.


From the Sundance warranty;

"Neglect, misuse and abuse include any installation, operation or maintenance of the spa other than in accordance with the instructions contained in the owner’s manual provided with the spa, including (but not limited to) the failure to maintain proper water chemistry and chemical balance and the use of abrasive or improper cleaners."

From the Dimension One Warranty


"EXCEPTIONS TO WARRANTY
The following items are specifically excluded from any warranty coverage:

9. Damage caused by failure to follow procedures defined in the owner’s manual.

11. Hot tub pillows, hot tub light bulb, hot tub filter element, and hot tub hose bib."

From the Marquis Warranty.

"This warranty is void if this Marquis spa or component (such as skimmer lid, removable jet fitting, etc.) has been subjected to alteration, misuse or abuse, or if any repairs on the spa are performed or attempted by anyone other than an authorized Marquis Spas service center."

"Misuse and abuse” shall include, without limitation, any installation, maintenance or operation of the spa other than in accordance with Marquis Corp. printed instructions (located in the Owner’s Manual) or use of the spa in a manner or for a purpose other than for which it was designed. Under no circumstances shall Marquis Corp. or any of its representatives be held liable for injury to any person or damage to any property, however arising."

"Items beyond Marquis control include but are not limited to damage resulting from; improper electrical connections; accidents; failure to follow procedures defined in the Marquis Spas Owner’s Manual; cleaning agents; and lightning and other natural occurrences."


Im not trying to beat anyone over the head with it, but I think its better that people be informed, than make an assumption that all calls are covered by a warranty.

[Vinny]

I agree with you!