tds bogus or true???????

[waterbear]

Okay, once again... I keep my tub at a minimum of 10ppm bromine. I do not need to shock as per industry standards in Canada.
As I said before, shocking is NOT what is done with a bromine system. When you add oxidizer you are converting bromine ions back into hypobromous acid....whether this is done with chlorine, MPS, or ozone is moot. The action of the added oxidizer creates hypobromous acid from the bromine ions. If chlorine is used the hypochlorous acid is immediately converted into hypobromous acid. The effect of 'adding shock' to a hot tub (as it is commenly referred to) is to raise the bromine level in the water when it has dropped. Adding more bromine to the water will not accomplish this unless an oxidizer is also present. Basic bromine chemistry. If you use tabs in a floater then you are adding both bromine and clorine or bromine and MPS at the same time....depends on the tab you use whether it contains chlorine (most do) or MPS (only one brand that I am currently aware of)
I'm am not really worried about residual bacteria, it's just something that I think about because a family in my province was hospitalized due to that exact problem ( hot tub bacteria out of control & the kids almost died! - it was an indoor tub which was not properly sanatized prior to draining & clearly not sanatized properly when they refilled it months later... nasty bacteria was found in the piping by investigators).
This is why proper sanitation of a hot tub or pool IS so important...and why I don't like copper/silver systems that say you can use reduced chlorine levels or only MPS in a hot tub! With bromine levels of 10+ ppm your tub should be very well sanitized....I would worry about developing bromine sensitivity with that high a level, however....bromine is a known sensitizer and the biggest problem with it's use is that many people can get a reaction from it. Some exhibit this right away...others develop it over time with exposure to the bromine. Also, it seems that 'hot tub folliculitis' is more commen in bromine santized spas.
I follow all the recommendations of my tub from the manufactor & have had perfect water in both of my tubs, always ( wish I could say that about my pool...lol).
Hang around on the forum and you will find that your pool is actually EASIER to maintain then your hot tub....I speak from experience!
( waterbear, I think you missed that I was being sarcastic in my last post..lol , sorry )

I don't put extra crap in my tub ( fragrances etc.), although I would love to scent my pool with Hawaiian Lily..lol, ( love that one; can't help but open a bottle & sniff it every week when I visit the hot tub store) ( btw, I have no intention of putting fragrance in my pool, okay? )

The question of this thread was asking if high TDS should be addressed & the tub dumped. It is my opinion that the answer is Yes.
It is only my personal opinion that a TDS of over 1450 in a hot tub, makes the water really yucky & not performing ( or feeling) as it should. Industry standards & tub manufactors concur with this opinion, however, chemists may or may not.
I further stated that I would keep my tub at 800- 1000 TDS ( if it were possible), as by my observations, that is when the water performs best ( for me & mine).

so again, the question of the postee was , should he dump his tub water?...
I still feel that he should have a second test done at another store & see what the levels are... if the TDS is high, I still believe he should drain & refill, regardless if the water is "fresh".
He also said that he has the same water tested a few days later and the TDS was fine AND that the tub had just been filled....indicates a testing error. Also some places are using test strips to test for TDS....not very reliable. If you are maintaining your your tub properly and draining on a regular interval then the TDS test is not necessary.
And since the postee had water trucked in, I would consider either going with a different water company, or asking them to check the TDS prior to delivering.... ( which makes me wonder if it could be picking up residual particles from not having the truck cleaned out throughly...)

( ps- I have never seen my tub start to foam or had scum-lines... maybe because of regular maitenance or maybe because I drain the tub when it reaches 1200 TDS...)
Which I bet is around every 3 months or less. The effects of high TDS will be such things as foaming or scum. TDS is really only usefull as an approximation of how 'old the water is. There are hot tubs that are sanitized by SWGs so the TDS measurment for them will be totally useless since they will have a TDS of the salt level (usually around 3000ppm) plus whatever ionic solids are dissolved in the water such as calcium, magnesium , sodium , potassium, chloride, bromide, etc. In some reagions the fill water can have a TDS higher than the recommended levels and yet the tub or pool can be operated and maintained without any problems. In acutal practice TDS is about as useful a measurement as is the Langelier Saturation Index (which has been the topic of MANY discussions on here.

One final note....you stated that your hot tub is essentially a 'closed system'. You forgot the main thing that makes this assumption wrong....the bathers entering the tub. IF you never used it and no one ever got into the tub between each drain and refill then it would approximate a closed system much better. The first time someone enters the tub it stops being a closed system because of what the bather introduces into the water (sweat, fecal matter, body oils, etc)!

[turbottt1]

For the reord. I would love to see test readings of 1000-1500. When we use to worry about the tds measement I'm talking 5000. Read second post. New water, only chems. needed, and two bathers. Test results 2500-5000. Yes there were strips used. First thing you say. strips are no good. We always take a pool sample with us too.[ 1250-1500 range. We go to the local pool store and also up to our artic dealer results close to the same with multi. test done each time. Our tub is sitting at 5000 right now. I dare you to fine cleaner, better smelling, and easier water to care of anywhere. no foam, no scum line nothing and we use no defoamers, scumballs,etc. As far as cleaning the tub I'm not sure how everybody else does it but we first run the cleaning product[ fresh start] for 24hrs. before dumping the water, dump the water, suck out all lines, flush with clean water all jets, filters,lines, etc. which fills the foot well and dump that water, suck lines, etc again, take our chlor. shock mixed wipe down all surfaces including the bottom of the cover and refill. We have had the same trucking compant bring us our water multi. times this year including 25" of water for the pool.[ 30' round] We have discovered that we have been adding sodium bromide to the water weekly. Could we be picking up a false reading because of over high levels of this???? steve

[RavenNS]

Steve, that seems plausible to me ( that TDS is that high) given the early postings about salt water pools; but I'm not a chemist.
It would be interesting to see what TDS you'd have if you weren't using a sodium based bromine.

( I wouldn't necessarily conclude that the TDS readings were false, I could guess that they are really high because of heavy salt)

You certainly are giving your tub a thorough cleaning...lol

(I wonder : Could the sodium be the ingredient that is bothering your burn, more so than the bromine?)
Bromine usually helps skin conditions. not only did it help with the stuff that I mentioned before, but it helps with problems like psorisis too.
- of course, salt can help with many infections as well...

well, If you are happy with the tub water, then ignore the TDS ( as long as it doesn't void your warrenty)...
otherwise, switch to a regular bromine & drain every three to four months (depending on the TDS)

Good Luck

[turbottt1]

Since he may see it here, I'm putting it here: "turbottt1" has been moved in to a 'banned' group, the "Bad Email Address" group, because his email address is dead. I use that group to prevent accidental emails from being sent to dead addresses, among other things. When emails bounce back to me, I automatically move users into that group. -Ben


Thank you for the cleaning adaboy.LOL! MY point to this thread is no one around here test with a meter. I've checked into them and wonder if this measement is worth the 350-400.00 investment in my own meter??? Thanks to the heads up by one of our members, I called and talked to one of the chemist who makes the product that we use. Thats when we discovered that it contains sodium bromide. As instructed weekly, I believe we have been overdosing on sodium bromide. Something we have been doing over the last 14 days is quite using our bromine and just using our shock [ 1oz.] after every use and once a week we shock with 3-4oz. Our taylor kit is not here yet, but our I believe oto[yellow] kit registers a level of between 3-5 ppm bromine. If I understand correctly with a two part system One part by itself does nothing and will not register on our kit. If my kit is showing 3-5ppm bromine than there must be bromine in the spa that our shock is reacting with???? I'm I correct??? steve

[waterbear]

Steve,
you are correct. ANY bromine based system needs sodium bromide in the water when the tub is initially filled. Tablets by themselves will NOT put enough bromine ions in the water to create a sufficient sanitizer level when the oxidiazer is added to the water for several weeks!
RavenNS, If sodium is the problems then Steve would get the same burns from either soft water or going into the ocean. I am sorry, but your theory does not 'hold water'....so to speak.

Once again I say TDS is a bogus measurement. In actual practice it means nothing. The main reason TDS came into use as a water parameter was NOT in bromine systems but in chlorine systems using stabilized chlorine. When trichlor and dichlor are used over a period of time TDS will rise (as it will with unstabilized chlorine) but so will the CYA (stabilziers). The vested intersts (manufacturers of stabilized chlorine and the pool stores that sell it) didn't want people to realize that the problems they were having with their pools was caused by the pools having too much CYA from continued use of stabilzied chlorine so TDS became the scapegoat and the reason they had to drain and refill. (Of course the problem is NOT our stabilzied chlorine tabs that you are using...its the TDS in the water! Your CYA level of 200 ppm is not the reason your chorine is not keeping the algae out of your pool...it's the TDS of 3000 ppm. It's not the high CYA that is causing the pitting of your plaster finish....it's the high TDS.) EVERY problems attributed to high TDS is KNOWN to be caused by overstabilization yet pools that have very high TDS (sometimes in excess of 6000 ppm) but are not overstabilized exhibit NONE of these problems....every pool with a SWG is a prime example!

Now if you would care to discuss the Langelier Saturation index (another bogus measurement)...

Also, bromine is a known sensitizer and many people have reactions from it. That is one of it's big downsides. I would like to know where you got the information that bromine helps skin coditions? If it is from the antibacterial effect then chlorine is equaly effective. In fact, chlorine is a more effective sanitizer than bromine. A FC level of 3 ppm is equivalent to a bromine level of 6.75 ppm!

[chem geek]

I would just like to respond to the earlier question about getting a TDS meter for home use. I suspect this isn't a great idea, though it's probably easier to get a reliable and relatively inexpensive TDS meter than it is to get an ORP sensor. TDS is most often measured by conductivity. This has several problems, however. First of all, it doesn't measure anything that isn't charged, so neutral dissolved solids aren't measured. Second, you have to plug in numbers into formulas for roughly what is already known to be in the water (CH, TA, etc.) since the conductivity measurement doesn't tell you the "weight" of the solid and "ppm" is a weight measurement. Finally, conductivity measurements are affected by the size of the charge, so an ion with a charge of 2 registers 4 times as much as an ion with a charge of 1 (a charge of 3 registers 9 times -- yes, it's the square of the charge that gets measured) so if you don't know what's in your water composing TDS, you're measurement will be bogus (probably too high).

So, bottom line, to the degree you already know a lot about what is in your pool or spa, then you have a chance of figuring out your TDS. The fact is that you can probably add it up yourself from the CH, TA, CYA, and salt (NaCl) (and maybe borates/boric acid if you use Borax). If you stick with BBB, then you won't have other junk including sulfates in your pool. Now with a hot tub that's using bromine and fragrances and all this other stuff, I personally think it's just better to change the water frequently regardless of TDS. As waterbear says, TDS is not particularly useful to know as a single total number -- it's the components that are important and there is no way of knowing if extra junk causing high TDS is a problem or not. If it's just plain salt, it's clearly not a problem.

I have TDS in my spreadsheet and it influences the boo-hoo'd saturation index (it's not so much that it's bogus, but that it's over-emphasized and I've improved upon it anyway ), but what is more useful is to know how much specific chloride ion there is, and sulfates, etc. since these influence things such as chlorine outgassing that are much more relevant and useful (though very hard to predict with accuracy).

Consider the following. If we can figure out why the pH rises in so many pools (both SWCG and non-SWCG) and can come up with something simple like keeping TA at 80 or 60 or something like that, then that will save a LOT on chemicals (acid) and will help keep down TDS as well.

Bottom line, save your money and try to focus on keeping things simple. Using BBB will significantly reduce the extra stuff that is in most pools -- clarifiers, KMPS shock (lots and lots of sulfate in that one), defoamers, enzymatic cleansers, sequestering agents, algicide, etc. etc.

Richard