swim pool cartridge filter cleaning using acid and TSP

[notrub]

I have recently been introduced to muriatic acid and to trisodium phosphate.   I have an Emaux salt chlorinator and cartridge filter system.  Using muriatic acid to control algae has worked out very very well.  Much much better than all the costly swimming pool products sold under various brand names.  I have been using sodium bisulphate to lower my PH level although muriatic acid can be used for this too. 

 

I rarely add salt or chlorine although a recent algae bloom taught me the lesson to catch it quickly b4 it gets out of hand.  That was b4 using the acid and I added lots of powdered chlorine to get the water clear again.  Mostly the salt generator keeps the chlorine levels to an acceptable level.  

 

Filter cleaning has been a costly, time consuming learning curve and I am writing to share my solution and ask for comments.  I tried using floor cleaning soap with predictable results if the cartridge is not thoroughly rinsed rinsed before reinstalling.  A big mistake was to use a HP spray to wash as this simply drives the dead algae and dust into the filter membrane.  'Hosepipe pressure only' works very well on a properly cleaned cartridge.   

 

I have recently been soaking my filters in a TSP solution with a soft brush brushing rinsed and let to dry in the sun.  Drying seems to make a difference but don't know why.  Sunshine kills bacteria and with several filters it does not interfere with the process.

 

My friend uses muriatic acid only for cleaning and that works very well.  However, I have just been reading that the acid locks oil etc. into the filter and it should be cleaned b4 the acid soak.  So for me that is a TSP soak, rinse then acid. each for a day or 2 in a weak solution.

 

These are private pools so there is not a big issue with tanning oils or dirty bodies/feet and swimsuits/shorts.  Mostly algae and dust.

 

Here is a question.  How does the TSP react to the acid?  Will it cause the acid to become neutralised or create some deadly combination?  I intend to give the TSP soaked cartridge a good water only soak and a rinse before putting it into the acid wash.  Then a good water only soak following the acid bath and hosepipe spray down.  Then dry.  Don't plan on any acid neutraliser as this is already in the pool anyway.

 

Any comments will be very welcome.  Thank you.

 

  

[Bagwain]

I wouldn't recomend using acid for cleaning the cartridges. You will shorten their life. Just soak in disenfection solution. Monosodium Bisulphate is good. Basically baby bottle cleaner, flush from the inside with a hose & let dry in the sun. Acid should be used mostly to reduce pH as this will always rise in a salt pool. Once every 6 months is a good idea to clean your salt cell. 1st with dishwashing detergent then 20% acid & 80% water soak. for a few minutes. Your brand of chlorinator is the most troublesome machine on the market. I had 10 blow in one condo in the 1st yr due to unstable power. A shop nearby that I visit regularly has broken ones on the floor. They are totally overrated with ther output! I use & recommend an Australian brand & made range of machines that are arguably the best on the market with extended warranties. Bullet proof!

 

I don't like cartridge filters on swimming pools. Jacuzzi's ok!

Sand filters with "Eco Clear" recycled plate glass (Clear in colour) as the media, is the best.

(Not the recycled bottle glass that is multi coloured)

Eco Clear.pdf

[notrub]

Thanks for your comment.  Now that I have found out how to clean the cartridges I am a happy guy.  Unlikely to change over to a sand filter due to cost etc..  What you say about the Emaux salt chlorinator is very interesting.  My friend bought the same equipment as me and his chlorinator literally exploded.  He was near it at the time but was not injured.  Had he been looking at it he would have been blinded.   To be fair, we had problems with stable electric supply at the time.

 

I have a bag of Sodium Bisulphate that I have been using to lower the PH but never thought about it as a filter cleaner.  I have only ever seen dishwasher soap for sale one time in TOP supermarket and it was 4 or 500 baht for a small box.  From what I understand it contains a degreaser similar to TSP but am not sure what it is.  

 

I put about 1 KG of tsp into about 30 or 40 (?) gallons of water (one of those big blue chemical barrels 70cm high by 40cm dia.) and that seems to work very well.  3 or 4 day soak.  I am following this with a weak acid bath just to see how it turns out.

 

Using the muriatic acid in the pool has been a big improvement over the 'clear pool' and other products that cost the earth and don't work nearly as well.  

 

What is the name of the Australian company you mentioned please?  I am not keen to change the emaux one but would go for another brand if it fails. 

 

It seems that you have many pools while I am just trying to keep my little 4x8x1.5 effort functioning clean and clear.  It is my first pool and we constructed it ourselves following You tube research.  We used big blocks and filled the cells with rebar and concrete.  Then tiled onto a rendered surface.  It has been a steep learning curve.  The few other pool owners that I spoke to have had them constructed for a high cost. 

 

Nice to exchange a few ideas, thank you.   Here is my home.  A bit messy but comfortable.  Kind Regards

 

 

 

 

[Bagwain]

I renovate pools and have a company based in Pattaya for over 15 yrs with over 20 yrs in the industry. 2 yrs as consultant at Ramayana for water quality control & chemical balance & handling. Autherised dealer for PuraPool range of equipment. Arguably the best on the market! Message me if you want brochures. The top of the range machine is the "Oxy UV Minerale" that uses pink Himalayan salt and creats active oxygen molicules that does the sanitation. Sriracha Hotel as it installed. P.s The reason you use dishwashing detergent on the salt cells 1st is to get the grease & oil off as acid won't effect either. Cheers 

Edited November 22, 2019 by Bagwain

[notrub]

Hello again,  When I first posted about the filter cleaning it was just to share my experiences.  I was a building contractor and had worked in Canada, US, UK, France and a bit of volunteer work in Nepal in the mountains.  That last one was assessing and repairing health posts for a charity in remote areas of the country.  I have a thirst for knowledge and like to learn and share when I can.

 

If it is not taking advantage of your position as a professional I have a question to ask.

 

By coincidence I have just had a surprise problem with a mystery leak in my pool.  The water level went down 10cm overnight and a further 5 or 8cm the following day, yesterday, and then stopped.  I was waiting to see if it would drain completely or stop at the return jets level or the lights but it did not go below the line of dark blue tiles.  Above the jets and lights and about 15cm below normal water level.

 

I have just finished inspecting the grout and tapping the tiles all around that level.  Although a few tiles don't sound so 100% good (95/100) the grout is solid and without any cracks or visible defects.  

 

I have drained the pool by about 4 cm below the leak line and will let it dry.  I will then apply a good, soak in, coat of waterproofing agent to the grout and let dry before refilling the pool.  We used swimming pool tiles, glue and grout about 1 1/2 years ago.  I was here when the tiling was being done and they soaked the render before gluing the tiles.

 

I am thinking that at the level where the leaking stopped the tiler may have used old grout or some such thing.  It all looks the same in colour and texture, however.  It seems that dropping 10cm overnight is a lot for it to just seep away.  I think that is about 2 1/2 M3 (?).  I have visually inspected the area around the pool (but it is tiled) and the pump and pipe area for extra water but can see nothing unusual.   

 

So, if you don't mind me asking this-what do you think?  

 

If you prefer not to comment I will understand and thank you for your earlier advice.

 

Regards, Burton

[Bagwain]

No problem Burton.

Sounds like you have already done the right things.

The leak is generally found the way that you did it and it most likely be at the level it stopped at.

You loose about a finger in evaporation per day, however that varies a little depending on season with it being a little more in winter here. Strange but true. I can't offer anymore advice to what you have already done.

 

I am not in favour of using blocks and steel filling them with concrete the way you built your shell. Too late obviously. You may need to look at regrouting. I use Weber Swimming Pool grout that comes in the 20 litre drums. It has 2 part mix so the natives can't get the mix wrong. However I do have to stop them from adding more water if they think it is going off.

 

I hope you find the leak asap. If water get s to the shell it will get more acidic quickening the degradation of the under surface.

 

Good Luck.

 

 

[notrub]

Thanks for your reply.  I filled to pool back up yesterday afternoon and it has maintained exactly the same level since then, about 18 hours (I filled it to a grout line).  So it looks like the problem has been solved.  Hope so.

 

I used Weber 2 part grout and swimming pool adhesive tiled onto a render that I had put PVA and waterproofing additive into.  Quality pool tiles too.  I am about 100 km away from anywhere and the cost to get a contractor up, or down, here was a lot.  My pool cost a lot less than 500K baht all in including over 100m2 terrace tiled onto a concrete base.  

 

I was a contractor so I thought why pay 1,5M baht just for a small pool and a little bit of tile surround?  I had local people doing the heavy lifting and was here the whole time so it was OK.  We found a supplier of 'super blocks' (about 14cm thick) and used lots of rebar and good concrete on about a 15cm slab with 6mm bar in it.  Good drainage under too as I had read of the dangers of pools floating on improperly prepared earthworks.

 

My friend Peter built one exactly the same using my excess blocks (I had to buy a truckload from Korat) except he did all the blockwork himself and the tiling too.  My missing water is the first  problem either one of us has had, fingers crossed.  That is, after finding out about muriatic acid.  There were some adventures with algae before then. 

 

We just snapped a level line on the final course of blocks and cut them off with a grinder.  It is good to see the water level on the grout line all around the pool.  Not something I take for granted having built 2 houses here.  There have been mixed results when setting  a standard of quality in the morning and it being continued through to the end of the afternoon.  Nothing surprises me any more but this variation of workers following instructions did not start in Thailand.  I am sure you have had similar experiences.

 

Thanks again for your comments and information about salt chlorinators. 

 

Kind Regards, Burton