Same Taylor Test Kit K-2005 - (Different Results)

[wapate]

I recently purchased a new Taylor K-2005 drop test kit. My pool cleaner has the same kit. My alkalinity reads 120, the pool cleaner reads 80. A big difference. The water for both tests came from the same container.
Anyone have a clue as to how this can happen?????????????

[Watermom]

There is no way for us to determine why results are different from one person and kit to another. Maybe his reagents are old? If it were me and my kit was new, I'd probably go with my results. But, having said that, an alk of 80 is fine as well as an alk of 120. What kind of pool is this?

[waterbear]

ARe you both testing the same way? The proper way to do that test is to keep adding drops until one more drop produces no more color change and then don't count that last drop. I suspect he might be stopping at the first color change from green to red and if he added anouther drop the read would become more red. Also, his regents could be old and if the titrant is left uncapped it can become stronger as water evaporates and that would throw the results off. I suspect his kit is kept in a hot car or truck much of the day.

[wapate]

Since posting, I'm thinking my reagents may be old. I don't know how long my test kit was sitting before I purchased it, The pool cleaner goes through many bottles, so I would think his is probably newer than mine. I'm taking my water to a pool company, let them test, and see what they come up with. If they are in line with the pool cleaner I will have my answer. I just drained my pool after 14 years because I had what I call "Cake Icing Dribbles" on the walls. My TDS'S were off the scale. I'm now in the process of re-balancing my chemicals. It is a gunite pool. With the TDS'S removed, I want to balance the chemicals with as little addition of chemicals as possible. Thank's

Didn't think about temperature. Now you mention it, his reagents are kept in the back of his truck, exposed to the hot sun all the time.

[waterbear]

Didn't think about temperature. Now you mention it, his reagents are kept in the back of his truck, exposed to the hot sun all the time.

And there you have it!

FWIW, high TDS (Total Dissolved Solids) in and of itself is not a problem. It is the actual ionic species that make up the TDS that can be problematic. For example, if your TDS is mostly sodium and chloride ions (from use of chlorine as a sanitizer) then they really have not negative impact on your water. On the other hand, if they are cyanurates from continued use of stabilized chlorine, calcium from continued use of cal hypo or from hard fill water, sulfates from use of dry acid and non chlorine shock, and metals such as copper form algaecides or fill water then they can be problematic. Your 'cake icing dribbles' sound like you have had some water balance issues over the years. It is not necessarily a results of the TDS but more likely a result of how well you regulated your pH and what your calcium saturation index was.

[wapate]

I'm sure you can relate to this. I live in an area of Florida where there are a lot of pools and a lot of so-called pool experts. Last year I had what I'll call "Dead Algae Dust" accumulate in the bottom of the pool. I was clueless as to what it might be. Then I had the "Cake Icing" deal. I have in my files, a water report for every month the past 14 years. This is, and has always been a saltwater pool of 10,000 gallons. It has been shocked 3 times in 14 years. Never used dry acid. Has never tested positive for metals. The calcium level has always been around 200. Have never put an algaecide in the pool. This pool is known in this area as the one everyone wants theirs to look like. When the pool refinisher came to buff all the "Cake Icing" from the walls, he said he had never seen a 14 year old finish in as good a shape as mine.
After much research on the web pertaining to my 2 problems, (Dead Algae Dust & Cake Icing) an article on TDS'S seemed to explain what my problem MAY be. Not saying it is, but that's all I was left with.
There is no doubt the "Cake Icing" was calcium, but what caused it, taking into account the care I have given this pool, remains a mystery to me.
Thank You.............

[waterbear]

Where in Florida. I have lived in S. FL and currently live n N. FL. You said it is a salt pool, which SWCG do you have, and how well do you keep your pH regulated? High pH is the main factor that can cause calcium to precipitate out fo the water. If you are only testing your water once a month that is not enough to keep tabs on the pH in a salt pool. Also, how high is the TA of your water? Areas of Florida have water with very high TA.

I have never heard of "dead algae dust" , What exactly did it look like? To me it sounds like you have had problems with calcium precipitating out of solution. This really has nothing to do with TDS but everything to do with water balance (and most importantly pH since pH spikes are was tend to create the condition for this to happen. I would be very interested in seeing a full set of test results and knowing a bit more about what equipment you have (pump, filter, SWCG, etc.) and how often you test your water and make adjustments.

[wapate]

Hello Again....... I have a Jandy system now. Prior to that I had a Chlromatic. After 11 years I needed another cell Chlormatic was out of business, so I had to get a complete Jandy system. My original aaaand still being used equipment is an American Products Ultra Flow Pump & a 22 Inch Eclipse sand filter. Sand was changed when the new Jandy was installed. It looked as good as the new sand. None of my equipment has ever been rained on, or had sunlight hit it. It is all enclosed in a special room I designed for it when I built my home. I have always had a pool cleaner who tests the water weekly. The water reports I got was just to see that he was keeping my water balanced. I'm sure the PH has not always been in range, but from the looks of the pool, it's been pretty close for 14 years.
The Algea Dust is just that. You touch it underwater a disappears into the water till it settles again. I have seen posts about algae dust on the web before. Very hard to get it out of the system. My PH is hard to get below 7.9 and the alkalinity wants to keep dropping. When I do add acid, I walk it in small amounts. Any idea there?
I live in Destin.

[waterbear]

So much misinformation, where to being!?!?!?!?!
Algae dust you are describing sounds like mustard algae and is caused by not having a high enough FC level in the water. Once you get it you are correct that it is hard to get rid of.

I'm sure the PH has not always been in range, but from the looks of the pool, it's been pretty close for 14 years.

<facepalm>
The calcium scale "cake icing" is a water balance issue. Peroid. You cannot tell if the water has reached scaling conditions by looking at it AND YOU CANNOT TELL THE pH OF THE WATER BY LOOKING AT IT, YOU HAVE TO TEST IT! PERIOD!
Both of these together are a good reason to fire the pool guy and start doing it yourself since the fact that you have had these problems and

My PH is hard to get below 7.9 and the alkalinity wants to keep dropping. When I do add acid, I walk it in small amounts. Any idea there?
I live in Destin.

As far as walking acid to lower pH vs slugging acid to lower TA, it's a myth that persists in the pool industry even though it has been thoroughly debunked many years ago! (The linked article is from 1995!)

IF you are having problems keeping the pH down in a salt pool lower the TA. The main cause of pH rise in a salt pool is from outgassing of CO2. Keep your TA at about 70 (and adjust calcium if needed to maintain your calcium saturation index). Keeping your CYA at the recommened maximum (for Jandy that is 75 ppm) will also help by limiting cell on time. You then want to maintain the FC level at a minimum of 5% of your CYA (so keep it no lower than 4 ppm at all times).
When you lower the pH (it makes no difference at all if you walk the acid or slug it other than potential damage you can do to the pool by slugging it) don't lower it below about 7.6 and wait for it to climb above 7.8 before lowering it again. The lower you put the TA the faster CO2 will gas off.
Adding acid will lower BOTH pH and TA but it will lower pH much faster than it lowers TA, Depending on the TA of your fill water you might need to bump up the TA from time to time with baking soda (in Florda that is doubtful) but you want to keep your TA at 70 ppm and don't worry about raising it until it drops BELOW 60 ppm.
To lower your TA it is a process, you drop the pH to 7.0 (and not lower to prevent damage to pool surfaces and equipment) and then allow the CO2 that has been created from the bicarbonate (TA) in your water to gas off. The act of adding the acid lowers the TA, allowing the CO2 to gas off brings the pH up without causing the TA to rise again. Aeration of the water will speed up the outgassing of CO2. There is a sticky in the forum with full instructions on how to lower TA if you need to do so.

Once you get your water in better balance and are able to keep it there you might consider adding 50 ppm borate to your water to introduce a secondary pH buffer (in addition to the bicarbonate buffer we call TA) that effectively holds the pH at around 7.7 to 7.8 for a longer time than without borate. As an added plus the borate has algaestatic action and will help keep the mustard algae at bay.

Bottom line is this, just because you have owned a pool for 14 years does not mean you have been caring for it properly (and it is not your fault because there is SO much misinformation that the pool industry keeps repeating, some of it because of ignorance and some of it to keep chemical sales at a maximum.
Now would be the time to learn what to do so you do not repeat the mistakes of the past (and if it were my pool the first step would be to fire the pool guy and take contorl of the pool myself!)

[wapate]

First, I want to thank you for starting me in the right direction. I have lowered my PH gradually, now 7.7, the TA (96 adjusted) has not changed much, so I'm heading the right way. My FC is 3, my CYA is 30 & my CA is 150. If I understand the S.I. correctly, that puts me close to 0. My goal now is to maintain that.
Wanted to clarify something I said earlier. When I stated my pool looked good to be 14 years old, I was not referring to the PH looking good. What I meant to say was that for my pool to look like it was plastered yesterday, and the fact I have never had a build-up in my SWG, the chemicals must have been close to correct. I've never seen a post claiming a pool can be way out of balance and have a finish like I do after 14 years.
Since I am now able to get much need help managing my pool and having an understanding more about my test kit........ The Pool Cleaner is history. Wish I had know then what I know now.
Thank You Again.........