Jump to content

Recommended Posts

Posted
You seemed to be implying that a DE filter is a primary filter, whereas all the DE filters I have seen, are installed down-steam of a sand filter, making it a secondary filter That is why I questioned it and I personally cannot see how it would work any other way.

i'm not sure who implied that but all the "zillion" pools i have seen in Europe and the USA had only DE filters as primary filters. any sand filter or bag filter would have been considered as stone age technology laugh.png

I haven't seen only one pool with a DE filter, but as a secondary and although that was quite small it was very expensive, the primary version of a low micron DE would presumably have to be quite large and quite expensive.

I keep hearing all this stuff about "old" versus "new technology", you should realise that bag filter materials have changed a lot over the years, like everything else. These new materials give them a wide range of mechanical properties and they are currently used extensively in numerous industries, including water treatment. I am still waiting for a real reason for not using them and so far everyone is avoiding that.

I have given my reasons for choosing them over other methods, all of which are technically valid, please be kind enough to do the same.

disadvantage of bag filters

no warning of clogged filter, sandfilter has a pressure gauge

usually small filter area, clogs quickly

need to be replaced at a cost

a mess to wash filter, and a place to do it needed, yak

down on you knees to replace it, once or twice a week

didnt I say this previously? perhaps in another topic? and its why I prefere sandfilters

  • Like 1
Posted
You seemed to be implying that a DE filter is a primary filter, whereas all the DE filters I have seen, are installed down-steam of a sand filter, making it a secondary filter That is why I questioned it and I personally cannot see how it would work any other way.

i'm not sure who implied that but all the "zillion" pools i have seen in Europe and the USA had only DE filters as primary filters. any sand filter or bag filter would have been considered as stone age technology laugh.png

I haven't seen only one pool with a DE filter, but as a secondary and although that was quite small it was very expensive, the primary version of a low micron DE would presumably have to be quite large and quite expensive.

I keep hearing all this stuff about "old" versus "new technology", you should realise that bag filter materials have changed a lot over the years, like everything else. These new materials give them a wide range of mechanical properties and they are currently used extensively in numerous industries, including water treatment. I am still waiting for a real reason for not using them and so far everyone is avoiding that.

I have given my reasons for choosing them over other methods, all of which are technically valid, please be kind enough to do the same.

disadvantage of bag filters

no warning of clogged filter, sandfilter has a pressure gauge

usually small filter area, clogs quickly

need to be replaced at a cost

a mess to wash filter, and a place to do it needed, yak

down on you knees to replace it, once or twice a week

didnt I say this previously? perhaps in another topic? and its why I prefere sandfilters

clap2.gifthumbsup.gif I get the feeling that Mr. "Cruze" has bought himself a new pool

smi20.gif...

Posted

clap2.gifthumbsup.gif I get the feeling that Mr. "Cruze" has bought himself a new pool

smi20.gif...

then this would be TH BAG

to be fair, bagfilters have advantages

small and easy installation, can be under skimmer next to pool so no pumproom needed

choise of filtation grade if you buy different grade bags

I also like the red color of TH CRUZEgiggle.gif

I am no guru on pools, only owned pools in TH for 8 years, used to have an outdoor jacuzzi/hot tub back home, cartridgefilter

but 8 years with sandfilters and bagfilters, I sure wont have any more bags

Posted

disadvantage of bag filters

no warning of clogged filter, clearly visible.... just look at it sandfilter has a pressure gauge by which time it is full of crap, some of which ends up back in the pool

usually small filter area, clogs quickly they are available in a range of sizes (up to 50,000litres+ if you wish), I could leave mine in for weeks if I wished.

need to be replaced at a cost first of all the cost is just £10 and secondly it will last for years.

a mess to wash filter, and a place to do it needed, not so, takes 5 minutes with a hose, on your lawn (full of stuff your lawn loves), if you are super lazy put it in the washing machine.

down on you knees to replace it, once or twice a week well mine is on a swivel arm, so I just raise it up to waist height.

I have already listed all the disadvantage of sand filters, so won't repeat myself. I told you these bags are the future. If after all this you are still unconvinced, feel free to keep flogging these old sand buckets and the spaghetti of pipework that goes with them.

didnt I say this previously? perhaps in another topic? and its why I prefere sandfilters

Posted

I told you these bags are the future. If after all this you are still unconvinced, feel free to keep flogging these old sand buckets and the spaghetti of pipework that goes with them.

My two oldest pools are bag filtered, and I am looking forward to the day they are history. Past 2 years my maid has been doing my 2 pools with sandfilters, but she wont go near the messy bags.

The fact the bagfilter pools more often have troubled water, I do not blame the bags for but their chlorinators and exposure to sun. Fact is when water need special treatment, its days with messy bags.

and I dont have a lawn for the stinking waste. hate grasspost-81971-0-35922000-1329111665_thumb.j

post-81971-0-55121000-1329111764_thumb.j

5 minutes to wash a bag filter? sure...... find stand and place it, roll out hose and open water, take off lid, basket out, filter out, take ring off, bring it over to stand in a bucket to avoid dripping, followed by 10 minuts hosing it splash all over clothes and shoes, clean up area, 30 minutes and done

sandfilter, move the valve, change a couple of lightbulbs in the house while backwashing 3 minutes, move the valve, wait a minute to complete rinse, done. and the waste is gone to the waist drain

Posted

I keep hearing all this stuff about "old" versus "new technology", you should realise that bag filter materials have changed a lot over the years, like everything else. These new materials give them a wide range of mechanical properties and they are currently used extensively in numerous industries, including water treatment. I am still waiting for a real reason for not using them and so far everyone is avoiding that.

I have given my reasons for choosing them over other methods, all of which are technically valid, please be kind enough to do the same.

there's one thing missing in your arguments. if i'm not mistaken you are living somewhere up north or north-east where the ambient temperature in "winter" is much cooler then down south. moreover, correct me if i'm wrong, you mentioned operating your pool since six weeks, id est the coolest time of the year. let's wait another 2 or 3 months and then repeat your claim that 1 hour filtering time is sufficient for your pool.

the primary version of a low micron DE would presumably have to be quite large and quite expensive.

that is correct. i don't remember how much my last DE filter was (bought in 1994) but the size was not bigger than the average sand filter used in Thailand.

More then one thing is missing from his arguments but I digress. A bag filter in modern times is primarily used for the purpose of capturing used DE from the waste water in commercial installations when they are cleaned as DE is very harmful to the environment, clogs up sewer and similar waste systems due to it's density when wet and causes cancer when dried and inhaled and even then only on the pressure side never suction.

When confined in an enclosed space ( I.E. container needed to use in any inline installation) they are veeeeery difficult to remove as the debris causes a very strong suction effect due to the pressure that was exerted on them while the pump was running and the lack of ability to relieve that suction after the bag coupled with the weight of collected debris. If installed on the suction side inline it WILL eventually suck air through whatever separation system is used reducing pump efficiency and eventually causing costly damage through pump cavitation.

If on the pressure side due to it's small size it WILL eventually either crack or also leak through whatever sealing system is applied. Maybe Allan is not aware of the fact that a "modern" DE filter is actually a modified, updated version of a bag filter only utilizing a more easily maintained and effective method of filtering by using DE as the flocculent to coat the "bags" or cloth in this case which improves it's capacity to remove debris without the continual need for oversight and maintenance by disassembly on occasion when required.

If one was installed on the suction side it most definitely, eventually will be sucked into the pump at some point due to sudden over-saturation, the bag gets overfilled and then splits which then causes a large amount of collected debris to enter the pump and starve it of it's critical cooling water flow causing it to melt from over-heating or jam the impeller causing it to fry the motor or at a minimum do serious damage to the pump internals, there is NO upside to a bag filter in the context which it is being considered for use, open mind or not, there are plenty of first rate equivalents available that made them obsolete in the first place.

All of these potentially expensive catastrophes nullify ANY minimal savings one might initially realize in it's installation and use and that doesn't even factor in the extra up keep and maintenance required..

Finally, the above examples are not speculation nor exaggerated in any way they come from years of REAL life, hands on experience of thousands of pools over decades and multiple professional seminars attended by the top companies and industry professionals..

BTW this is my last word on the topic that is permeating the board across threads now, if it still doesn't get the point across............Well some people are just incorrigible as there has been more then enough factual, first hand counter points made to draw a reasoned conclusion with..

Posted

clap2.gifthumbsup.gif I get the feeling that Mr. "Cruze" has bought himself a new pool

smi20.gif...

then this would be TH BAG

to be fair, bagfilters have advantages

small and easy installation, can be under skimmer next to pool so no pumproom needed

choise of filtation grade if you buy different grade bags

I also like the red color of TH CRUZEgiggle.gif

I am no guru on pools, only owned pools in TH for 8 years, used to have an outdoor jacuzzi/hot tub back home, cartridgefilter

but 8 years with sandfilters and bagfilters, I sure wont have any more bags

Yes but those 8 years of DIFFERENT comparable systems gives you "real world" experience to relate to and not conjecture. All of those features you mention are advantages on a FISH POND or a 1940's pool but not in a modern swimming pool when so many viable and more effective options are offered..

You also can not dismiss the bag filters from contributing to your problems, a first rate filter makes a massive difference to the maintainability of a swimming pool, especially under the environment described..

Posted

I keep hearing all this stuff about "old" versus "new technology", you should realise that bag filter materials have changed a lot over the years, like everything else. These new materials give them a wide range of mechanical properties and they are currently used extensively in numerous industries, including water treatment. I am still waiting for a real reason for not using them and so far everyone is avoiding that.

I have given my reasons for choosing them over other methods, all of which are technically valid, please be kind enough to do the same.

there's one thing missing in your arguments. if i'm not mistaken you are living somewhere up north or north-east where the ambient temperature in "winter" is much cooler then down south. moreover, correct me if i'm wrong, you mentioned operating your pool since six weeks, id est the coolest time of the year. let's wait another 2 or 3 months and then repeat your claim that 1 hour filtering time is sufficient for your pool.

the primary version of a low micron DE would presumably have to be quite large and quite expensive.

that is correct. i don't remember how much my last DE filter was (bought in 1994) but the size was not bigger than the average sand filter used in Thailand.

More then one thing is missing from his arguments but I digress. A bag filter in modern times is primarily used for the purpose of capturing used DE from the waste water in commercial installations when they are cleaned as DE is very harmful to the environment, clogs up sewer and similar waste systems due to it's density when wet and causes cancer when dried and inhaled and even then only on the pressure side never suction.

When confined in an enclosed space ( I.E. container needed to use in any inline installation) they are veeeeery difficult to remove as the debris causes a very strong suction effect due to the pressure that was exerted on them while the pump was running and the lack of ability to relieve that suction after the bag coupled with the weight of collected debris. If installed on the suction side inline it WILL eventually suck air through whatever separation system is used reducing pump efficiency and eventually causing costly damage through pump cavitation.

If on the pressure side due to it's small size it WILL eventually either crack or also leak through whatever sealing system is applied. Maybe Allan is not aware of the fact that a "modern" DE filter is actually a modified, updated version of a bag filter only utilizing a more easily maintained and effective method of filtering by using DE as the flocculent to coat the "bags" or cloth in this case which improves it's capacity to remove debris without the continual need for oversight and maintenance by disassembly on occasion when required.

If one was installed on the suction side it most definitely, eventually will be sucked into the pump at some point due to sudden over-saturation, the bag gets overfilled and then splits which then causes a large amount of collected debris to enter the pump and starve it of it's critical cooling water flow causing it to melt from over-heating or jam the impeller causing it to fry the motor or at a minimum do serious damage to the pump internals, there is NO upside to a bag filter in the context which it is being considered for use, open mind or not, there are plenty of first rate equivalents available that made them obsolete in the first place.

All of these potentially expensive catastrophes nullify ANY minimal savings one might initially realize in it's installation and use and that doesn't even factor in the extra up keep and maintenance required..

Finally, the above examples are not speculation nor exaggerated in any way they come from years of REAL life, hands on experience of thousands of pools over decades and multiple professional seminars attended by the top companies and industry professionals..

BTW this is my last word on the topic that is permeating the board across threads now, if it still doesn't get the point across............Well some people are just incorrigible as there has been more then enough factual, first hand counter points made to draw a reasoned conclusion with..

This is complete and utter nonsense, so allow my to amplify.........

Maybe you have only ever seen one size of bag filter, put 2 and 2 together and arrived at the wrong conclusion.

If I left my bag filter for 2 years and it got so dirty, it would first tear. If by some huge miracle it didn't, as a very last resort it would simply overload the pump and cause it to burn out. If you did the same with a sand filter and didn't backwash it would either do exactly the same and knacker the pump, or cause something to fracture or explode.

However, the build up of dirt and resultant pressure differential, happens gradually and so, long before this happened there would be some significant mechanical noise and before that, a change in pump note.

But even before that, what you are claiming is completely impossible because, the first thing to happen is that the bag would tear, causing the vacuum to unload immediately, this bag is a simple polyester or nylon fabric, not Kevlar, or that new spider's web stuff. Also my bag has a 5" steel retaining ring which cannot go down a 2" pipe.

My bag has been in now for 3 weeks since I cleaned it and, with the pump running, the pressure differential is such that it barely deforms the fabric at all. That is why it is impossible to measure the DP, it is so low. Since this is all there is in circuit, the pump is doing nothing except pumping against a 2psi head

As I said before is you undersize something, or oversize something you are likely to cause problems. If you undersize a sand filter it may explode, certainly won't be good , if you put the wrong sand in, it won't work very well either, so best not do those things.

Choose the right size bag and spec for the job, or pick the right sand filter and fill it with the right sand for that job. If there are chuckwows out there unable to do that and the systems fail it's not the fault of the system, it's the fault of the designers.

There are concrete pools out there with huge cracks in them, so do we say that "concrete" is no good? No, we engineer the dam_n things properly so they don't crack.

Bloody hell this hard work, I think I will bow out.

Posted

there's one thing missing in your arguments. if i'm not mistaken you are living somewhere up north or north-east where the ambient temperature in "winter" is much cooler then down south. moreover, correct me if i'm wrong, you mentioned operating your pool since six weeks, id est the coolest time of the year. let's wait another 2 or 3 months and then repeat your claim that 1 hour filtering time is sufficient for your pool.

the primary version of a low micron DE would presumably have to be quite large and quite expensive.

that is correct. i don't remember how much my last DE filter was (bought in 1994) but the size was not bigger than the average sand filter used in Thailand.

More then one thing is missing from his arguments but I digress. A bag filter in modern times is primarily used for the purpose of capturing used DE from the waste water in commercial installations when they are cleaned as DE is very harmful to the environment, clogs up sewer and similar waste systems due to it's density when wet and causes cancer when dried and inhaled and even then only on the pressure side never suction.

When confined in an enclosed space ( I.E. container needed to use in any inline installation) they are veeeeery difficult to remove as the debris causes a very strong suction effect due to the pressure that was exerted on them while the pump was running and the lack of ability to relieve that suction after the bag coupled with the weight of collected debris. If installed on the suction side inline it WILL eventually suck air through whatever separation system is used reducing pump efficiency and eventually causing costly damage through pump cavitation.

If on the pressure side due to it's small size it WILL eventually either crack or also leak through whatever sealing system is applied. Maybe Allan is not aware of the fact that a "modern" DE filter is actually a modified, updated version of a bag filter only utilizing a more easily maintained and effective method of filtering by using DE as the flocculent to coat the "bags" or cloth in this case which improves it's capacity to remove debris without the continual need for oversight and maintenance by disassembly on occasion when required.

If one was installed on the suction side it most definitely, eventually will be sucked into the pump at some point due to sudden over-saturation, the bag gets overfilled and then splits which then causes a large amount of collected debris to enter the pump and starve it of it's critical cooling water flow causing it to melt from over-heating or jam the impeller causing it to fry the motor or at a minimum do serious damage to the pump internals, there is NO upside to a bag filter in the context which it is being considered for use, open mind or not, there are plenty of first rate equivalents available that made them obsolete in the first place.

All of these potentially expensive catastrophes nullify ANY minimal savings one might initially realize in it's installation and use and that doesn't even factor in the extra up keep and maintenance required..

Finally, the above examples are not speculation nor exaggerated in any way they come from years of REAL life, hands on experience of thousands of pools over decades and multiple professional seminars attended by the top companies and industry professionals..

BTW this is my last word on the topic that is permeating the board across threads now, if it still doesn't get the point across............Well some people are just incorrigible as there has been more then enough factual, first hand counter points made to draw a reasoned conclusion with..

This is complete and utter nonsense, .

Yes I agree, so that's why your not worth acknowledging anymore. Have a rubbish life in your future swamp.. You're too obtuse and too much like arguing with a wall.. It's not up for debate, it's the facts as they stand, take it or leave it, you've no credibility to support you.... Good day!!

Posted

Having trawled the internet I cannot find that much evidence of problems with bag filters, although there could be some horror stories out there, if the system was incorrectly engineered.

I was reasonably precise when I designed my system, sized the bag and built the carrier for a long service life and it works very efficiently. As I have said changing the bag is quick and easy and so is cleaning.

My plant room is more of a store room, since it contains only a small pump and four pipes, with a small control panel on the wall. People who see it are puzzled by the lack of equipment and bemused by the simplicity of the system. Being so simple it means fewer things to go wrong. lower costs and easy maintenance.

My neighbour who has a conventional overflow pool has a huge underground surge tank, a plant-room stacked full of gear and a complicated array of pipework. His pool has just been cleaned, the water is now only very slightly cloudy, but has an oily residue on the surface, from the sun oils used by the swimmers and possible organic residue.

His pool has been out of action for most of it's life due to heavy algae and he says he is tired of fighting a lost cause with it. We measured the water temperatures yesterday, his was 31, mine 26, a bit nippy you may say but come summer, his will be unbearable mine wont.

Another German friend got caught by the recent floods and both the pool and underground plant-room were completely swamped, his wife was in tears and he was close too.

As you said I have little experience of pools in Thailand, but the above goes to prove that there are problems everywhere when things are not done correctly.

The purpose of these forums is to offer information and give people choices, solutions and ideas. It is not reserved for so called "experts" who think there is only one way.

I have just been asked to design a bag filter to fit in an overflow pool channel, so the guy can simplify his system too.

Posted
My plant room is more of a store room, since it contains only a small pump and four pipes, with a small control panel on the wall. People who see it are puzzled by the lack of equipment and bemused by the simplicity of the system. Being so simple it means fewer things to go wrong. lower costs and easy maintenance.

but where's the fun when hardly anything can go wrong? whistling.gif

Posted

ask any of the Des Jouax pool buyers past 40 years if they are happy hosing bags and buying new bags at a price. No pump room, no visible piping, pooldesign as simple as possible. Not worth the disadvantage in my opinion during 8 years use

Posted

ask any of the Des Jouax pool buyers past 40 years if they are happy hosing bags and buying new bags at a price. No pump room, no visible piping, pooldesign as simple as possible. Not worth the disadvantage in my opinion during 8 years use

no pump room? big disadvantage! where do the bag hosers hide the illegal Portwine bottles procured for consumption above and beyond what the Mrs allocates? huh.png

  • 2 months later...
Posted

I`m looking for a pool supply company in Chiang Mai that might carry expandable rubber plugs like these..

1939_9_ENPANDABLE_PLUG.jpg

Size around 40mm (1" 5/8) that will expand to around 45mm or size 8.

They are used to block an open end and when inserted and tightened expand to create a leak proof plug.

Anyone seen them?

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • Recently Browsing   0 members

    • No registered users viewing this page.



×
×
  • Create New...