Test Your Water Source

[Mickey Moose]

Before starting my own maintenance at the beginning of October I read through numerous posts in this forum and elsewhere. Surely I just missed any that suggested testing your water source but I did just that the other day. It was really eye opening to compare those results to those of my pool. It gives a valuable perspective. One can better know what to expect of their pool and how that relates to maintaining balance.

My [rookie] suggestion to everybody starting out with maintenance is to test your water source just as with the pool. Keep in mind that the chemistry of a water source is not constant and forever so to take my recommendation one step further test the water source periodically. With what frequency I can't suggest as this is new to me too but i am going to start monthly.

-Mickey

 

[JoyfulNoise]

It's not a bad idea but I wouldn't do it more than quarterly. The only parameters really worth testing are TA and CH. There's no CYA in municipal or ground water and the pH is mostly irrelevant as fill water, once added to a pool, will shift it's pH according to the changes in alkalinity. Phosphates would be good to check in municipal water supplies as some older cities heavily use phosphonate scale and corrosion controlling agents. The long term build up of phosphates can make water more reactive to algae blooms. Salinity can also be measured as well in municipal supplies because municipal suppliers try to target a specific TDS value and they will let salt and CH levels fluctuate in order to achieve those goals. For example, my typical fill water analysis looks like this -

pH 7.8-8.2 (8.0 average)
TA 90-120ppm (100ppm average)
CH 250-300ppm (280ppm typical)
Phosphates 0ppb (not detectable)
Chloride 160ppm (typical)

I would say fill water chemistry is more of an issue in arid climates because pools with high evaporation rates will concentrate those ions. Areas with a lot of rain fall don't need to rely on fill water and so the rain water can basically be ignored except for its dilution effect, i.e., just consider it "pure" water.

Pool owners drawing from a residential or community well should have the water tested for iron and copper (use an outside lab to do the testing if you can). In many areas of the US, ground water can have significant levels of iron in it that will require treatment to remove before the water enters the pool. Or, if it can not be removed form the source easily, then one needs a metal management strategy for the pool water.

 

[kimkats]

Before starting my own maintenance at the beginning of October I read through numerous posts in this forum and elsewhere. Surely I just missed any that suggested testing your water source but I did just that the other day. It was really eye opening to compare those results to those of my pool. It gives a valuable perspective. One can better know what to expect of their pool and how that relates to maintaining balance.

My [rookie] suggestion to everybody starting out with maintenance is to test your water source just as with the pool. Keep in mind that the chemistry of a water source is not constant and forever so to take my recommendation one step further test the water source periodically. With what frequency I can't suggest as this is new to me too but i am going to start monthly.

-Mickey

Mickey, that IS something that is VERY important for everyone to do. I tend to post on the "Under Const" more and do tell them to test their fill water so they know what to get ahead of time so they will be ready.

I also suggest the "fill test" finding be put in the lid of the test kit or even better on the front of the small notebook you keep your test results in. I find logging your results helps you learn your pool's needs better.

THANKS for reminding us of this!

Kim

 

[SwimAustin]

While it is irrelevant to managing my pool, I found it interesting to discover my city water has chloramine (2 ppm CC) instead of chlroine (0 ppm FC). Turns out this has become quite common, but I had no clue until I looked it up. It is an important consideration for people using the water for fish.

 

[JoyfulNoise]

While it is irrelevant to managing my pool, I found it interesting to discover my city water has chloramine (2 ppm CC) instead of chlroine (0 ppm FC). Turns out this has become quite common, but I had no clue until I looked it up. It is an important consideration for people using the water for fish.

They probably use low levels of chlorine at the treatment plant but then use monochloramine as the secondary sanitizer because it lasts longer, kills effectively over longer time periods and is less corrosive to the distribution system. That's the most common approach used by municipal water suppliers.

And yes, very bad for the :nemo:

 

[kadavis]

Have you ever tested for nitrates?

 

[Caco]

I got the last full water test from my Council, just asked and they provided it to me at no charge. Full chemical analysis, including for pesticides and herbicides. It was a very interesting read
They did mention it is a spot check and will fluctuate, especially after rainfall or low flow when they have to adjust the chlorine
Mine showed nitrite at >0.002 and nitrate at 0.95 g/m3
Interestingly my LSI at source is -1.6