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Posts posted by moishe

  1. deld,

    have you tried the CalTreat?

    use a water softening cartridge:


    These cartridges are 2.5" (6.35cm) x 9.75" (24.765cm), giving a max. volume of about 3l of resin if filled to the brim. My LT8 contains about 27l of resin, if I calculated correctly. So If I was going to fill my 1600l (423gal) tub using 260ppm CH tapwater aiming for 130ppm CH, I would expect to go through somewhere around 9 cartridges (or regenerations) for a fill. Your water is even harder than mine, so you might expect to go through 10 on a same size tub.

    10 cartridges cost 190$ (or alternatively 9 overnight regeneration cycles, which means it would take you well over a week to fill the tub using one cartridge).

    So you might want to look for a larger filter.

  2. Now I've found something that works: I've obtained by online auction for somewhere around 50€ a water softener normally used with professional Italian coffee makers: The DVA LT8. The pictures show it after I fitted a couple of German standard garden hose quick connectors to it.


    According to the specs it softens 900l of 22°dH (400ppm CaCO3) water before it has to be regenerated using 1kg of salt. The water here is said to have 20°dH (I measured by multiple titration 260ppm CH as mentioned in the first post above).

    I estimated that I would be able to fill my 1600l tub in one go (without regeneration) and come out around 100-130ppm. As I didn't quite trust that estimate, I regenerated once at half fill. I had to add 100g of calcium chloride dihydrate to bring it back up to 120-130ppm CH from the resulting 60ppm CH. Next time I will go by my original estimate... :-)

    One thing I'm not quite sure about is what do I do with the water softener while it is not in use. I will only need it every couple of months, when I refill the tub. During the interim there is always a residual amount of water in it, keeping the resin wet and therefore the whole container humid. Is this harmful? Will I have to decontaminate it before use? Will a regeneration cycle with that 1kg of NaCl provide sufficient decontamination? Or will I have to make an effort to take out and dry the resin before storage?

  3. Ok, zeolite was an interesting idea, but it's not practical for this application.

    It comes almost in powder form and the sieves that are available at acceptable prices are just not fine enough to contain it. Bottom line: You can't filter water though zeolith without bringing at least some of the zeolith into the water and therefore the pool. Thankfully the stuff sticks together and deposits at the water line, so I was able to get it out within a week or so and didn't have to change the water. In its normal use in washing detergents this is irrelevant as it is drained together with the water it softens.

  4. Zeolith A is so cheap since it's so widely used as a water softener in washing machine detergents. If I understand correctly, for this application it inclucedes natrium ions which are exchanged for the calcium ions, so it seems to be set up to work just like a resin with the main difference being that resins are usually regenerated for multiple use and this stuff is usually used only once.

    So I've obtained some from a source for diy modular detergent components and I'm almost ready with my filtering setup, so I'll be able to report in a couple of days.

  5. I can't really comment on Leisureteq.

    With my Lamotte kit the main issue has been drying the equipment after use. I don't want to get too much humidity in the case. Therefore I recently set up a drying rack using some shishkebab sticks and a leftover wooden block:


    Better ideas, anyone?


    As far as getting search results. the terms you want to search for are OTO, DPD, and FAS-DPD if you are looking for info on chlorine testing for pools and spas since these are the terms that are used, not the chemical names.

    I hadn't commented on this earlier. The problem with search results is that search engines have a heck of a hard time giving good results on terms as short as these. Some simply refuse searching for 3-letter searchterms.

    [end edit]

  6. HEDP seems to stand for a number of things. I expect you mean 1-hydroxyethan-1 C2H8O7P2 or CH3C(OH)(PO3H2)2 . This seems somewhat hard to come by at a reasonable price, unless what I need is like a really miniscule amount per water change. We're talking about 30EUR plus shipping for 2g at 96% purity! [EDIT] At your suggested 1 to 10mg/l I'm looking at 1.6 to 16g per water change, so I'll be somewhere between 30 and 250EUR. This is not promising. [/EDIT]

    By what I can see looking at the Vanishing Act Calcium Remover, I am suspecting it could be simply a bag containing a molecular sieve, such as Zeolith A, which is readily available here and really cheap. The only drawback I see is that I will have to vaccuum it out afterwards if I can't contain it in some kind of bag like the one Vanishing Act comes in. As it's a hot tub, I wasn't planning on getting a vacuum...

    http://www.ultrachem.in/zeolite-a.htm mentions an average grain size of 4microns. Don't know whether that's just manufacturer-specific. I'm considering obtaining a 1micron filter bag like the ones at http://www.filterker...lterbeutel.html and simply hanging a scoop of Zeolith A in the skimmer/filter intake. Do you think this is worth trying?

  7. After a couple of days worth of experience using the kit mainly to test CH and TA and occasionally the other parameters I must say I am quite impressed and satisfied. The tests are easy to perform and the results are clear cut.

    The FC test gives an unequivocal reading as the pink changes to clear dramatically as the last drop is added, pH is really easy to read using the Comparator slide, the ALK test gives a rapid change from green to red within one drop so the reading is clear. The only test that is slightly unclear is Calcium Hardness, in my case the CH is over 400 and I am not sure whether I should stop adding drops as soon as the colour starts to change to blue or when it has fully changed.

    During titration I frequently see a color change limited to the area where the drop enters the liquid to be tested, which either resolves on its own or through my swirling the test tube. Sometimes on the last two or three drops a beginning color change can be noticed, which does not resolve. The latter would be what you're describing.

    I understand you are supposed to follow through until the color change is complete.

    I suppose you could subtract half a drop for the calculation to reflect the early start of a permanent color change, but as with any measurement you have to realize that the result will not be more accurate than the mode of measurement allows. So measuring The TA using a dropwise titration at 20ppm per drop, using 10 drops until the color change is complete, you will get a value of 200ppm which would be exact up to +/-10ppm at best. If you subtract half a drop for early starting color change, this would give you a value of 190ppm. And I would think that this would have to be interpreted with the same absolute exactness of +/-10ppm at best.

  8. I live in an area with fairly hard tap water - 260ppm - and I have neither a decalcifier nor a well with soft water. Therefore I don't have the option of changing part of the water in order to lower the CH.

    I was targeting 130ppm and the local spa dealer sold me a liquid "hardness stabilizer", consisting of a "mixture of carboxylates".

    Adding about 25ml to my 1600l spa brought me down to 200ppm. Gradually adding up to 100ml more in steps of 20ml had no effect at all. The CH remains on a plateau of 200ppm.

    Looking through the old posts I only found one possibly fitting reference to carboxylates:

    There are other factors as well such as the combination of hard water (CH) with soap. This forms scale (soap scum) with calcium while the TA has very little to do with this. The soap scum is not calcium carbonate, but a precipitate of calcium attached to (usually) two soap molecules (fatty acid salts with a water hating long end and a water loving carboxylic acid group and it is that group that attaches to the calcium forcing the molecule to precipitate out of the water). As you point out, people bring things into the spa and the relatively low water volume per bather means that it doesn't take much to throw things out of whack. Though I agree that the body soaking in a spa can change the pH, I think it is important to quantify that before assuming that a TA of 60 is inadequate, for example.

    I am going out on a limb in suspecting that part of what is causing the high CH has been felled by the carboxylates and is probably now residing in the filter, but another part is still in solution and is not being touched by them?

    I guess 200ppm CH is acceptable, but I'd still like to understand what's going on...

  9. chem geek, thanks for your insight on this!

    You are certainly making a strong case for using borates. As as an end user I don't seem to stand a chance of getting them here, I'll just have to stock up on 20-mule-team on my next visit to the states... BTW: What's the mileage on a box?

    Yes, Aquafinesse is definitely available here and there's one on the way to me now. Thank you for pointing me there! They suggest to use it on every water change. Is that advisable or just them trying to sell more of their product?

  10. I've been looking around several shops and quite some time has passed...

    Is the enzyme product one made for pool/spa use? It sounds like a laundry product since sodium perborate is a non chlorine bleach and it not really used for pools and spas since it destroys chlorine and bromine.and is a sensitizer and irritant. (It is NOT borax!) You want to use chemicals that are made for pool/spa use.

    No, it's not made specifically for pool/spa use. I is advertised as a multi purpose cleaner. I realize it's not borax - I'll can the borax issue for now and wait for an opportunity to get some 20-mule-team from the states.

    None of the spa shops or specialists I've talked to over here have of have heard of any product with enzymes for spas. So if this stuff is unsuitable for use in following Nitro's Approach to Decontamination

    1. Use an enzyme to clean out your pipes, such as Swirl Away, Spa Flush etc. Add this product, run the jets 30 mins and let sit overnight. It will clean out your pipes and deposit the gunk along the water line.

    then I'm at a loss for what to do to combat the toilet paper syndrome I'm faced with.

    What use is the Schell-Chlor (Fast-Chlor if I remember my 5 years of studying German correctly) used for? If it is a cleaning or laundry product I would not use it since it might contain surfactants that you would not want in the pool/spa.

    No, this is definitely the Dichlor. And it is for pool/spa use.

    So the current status is: I'm all set up with test equipment (Lamotte) and all regular maintenance chemicals. Thanks for all your help on these issues.

    What's missing at this point is the right thing - enzymes - for a thorough decontamination.

  11. Just thought I'd give an update:

    I ordered the Lamotte Kit through Sword Scientific. They seemed somewhat confused, not getting their quotes straight and quoting me shipping costs in EUR which they then charged in GBP, but I finally did get the kit shipped to Germany within about 2 weeks at a total cost to me of 144EUR. Steep I must say, but the kit does look impressive. Will get to work with it shortly... :-)

    Thanks btw for bearing with my ignorance of abbreviations.

  12. Thanks, waterbear!

    I found something labeled Schnell-Chlor (i.e. speed chlorine) at the hardware store. The main ingredient is Natriumdichlorisocyanuratdihydrat which according to the chembook would translate to SODIUM DICHLOROISOCYANURATE DIHYDRATE, so I guess this is the right stuff.

    Also, in order to follow Nitro's Approach to Decontamination, I obtained some enzyme cleaner which just arrived today. The ingredients are <5% non-ionic tensides, 15-30% phosphates, 15-30% oxygen-based bleaching agent (Sodium perborate), enzymes.

    Two things surprise me:

    1. if the enzymes make up the unspecified remainder of the volume, they would be around 35-69% of the cleaner. Can this be right - and can it be the right stuff for the job?
    2. Sodium perborate (with ten water molecules) sound a lot like sodium tetraborate decahydrate, but I guess it is not Borax. Anyway, I wouldn't want to introduce the cleaner's other ingredients into the regular pool water.

    Am I on the right track here?

  13. With the exception of Dichlor and a few specialty products everything you need can be found in your local grocery store.

    Thanks, Spanky, I needed to be told explicitly...

    I now got 250g of Kaiser Natron baking soda for €1,45 and 1l of Eau de Javel unscented liquid chloride bleach for €1,65, both at a dm drug store. I'll probably get the Eau de Javel at a better price in neighboring France as it's more commonly used there and I remember them selling larger jugs at for instance Auchan hypermarchés.

    1l of muriatic acid (Salzsäure) cost me €3,85 at a hornbach hardware store. So these are taken care of.

    Borax is no longer sold over the counter in the EU (since 2009 I understand). It does not seem to be considered a dangerous substance for passenger air travel though, so I am considering asking someone bring some back here from the US if it turns out I really can't get any here.

    So what remails open for now is Borax and Dichlor. Might someone knowledeable in chemistry please take a look at the links in my original posting regarding these?


  14. HornerXpress are in Barcelona, I got in touch with them a year or so ago but the Taylor 2006 was mega expensive and the postage was also very expensive.

    I discovered Sword Scientific just by chance but they are a great company, very helpful. They charge postage at cost but they are the European agent for Lamotte so they should know who they supply in Germany, worth a phone call anyway. They are not al all pushy but they have twice tried to steer me towards the ColorQ kits but also mentioned that they have started stocking the 7022 kit after recent interest!

    Regarding transport via aircraft, it is defiantly prohibited on aircraft out of the US but I have found no restrictions in Europe but then perhaps I didnt look hard enough.

    I just phoned international sales at LaMotte and they were very helpful. Turns out that Sword Scientific is actually their only dealer in Europe. Also, you are correct: the dangerous substances contained in the kit make passenger air transport a definite no-no.

    The guys at HornerXpress in Florida also seem to determined to make the sale for one of their dealers - there is actually one close to my location in Germany, whom I will contact today.

    One more question just occurred to me: As I understand it, the two kits are similar in quality, ease of use and reliability of test results. But how about quantity? Are they similar there as well or will one of them yield a substantially higher number of tests that needs to be considered when comparing prices?

  15. Hi all,

    I've been reading up on water mainenance here and at the pool calculator and am putting together the shopping list and trying to figure out where to get the items.

    I'm located in Germany, my hottub has about a 1600l capacity and the city water I'm using is at the high end of the hardness scale.

    For chemicals I was looking at

    • muriatic or dry acid
    • baking soda (which I probably won't need, unless I overshoot the acid)
    • dichlor/bleach
    • borates

    I was looking towards Afla Asear as a chemistry supplier. However, not being a chemist, I'm stumped by the multitude in quality, sizes and concentrations available.

    I wouldn't mind buying a mulit-year supply, but am also not so sure about the shelf life, especially with hygrophobic chemicals in our fairly humid climate.

    Am I even looking in the right place for these things?

    I know, thats a lot of questions all rolled into one... Here's a short list of the items I found at Alfa:

    Perhaps you would kindly steer me in the right direction.



  16. DaveH24, where did you get your test kit from in the end?

    Did you get any response from HornerXpress?

    I'm currently looking for a supplier in or to Germany, but going via UK will probably add too much overhead.

    Does anyone know, whether the chemicals in the Taylor K-2006 and LaMotte 7022 are safe&legal for airline travel in checked or carry-on?

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