Pool Water

I would think that dissolved solids are pretty much in equilibrium. There may be an ever so slight tendency to be higher concentration at ten foot, a ppm perhaps. If there is any stratification at all, prolly insignificant.

I guess you could allow the water to rest, take a sample at depth and at the surface, then test and compare.

Is watering the yard with pool water, having been dosed with whatever biocide that you have been using, going to give the lush and shiny green lawn result you are looking for? (I guess if you are squirting the old water over the fence onto the neighbor’s yard… never mind, that was a cruel and horrible thought)

Good suggestion.

I have a suction hose already at the bottom.

These projects take more time, at 78, than they did 20 years ago.

But, I have everything to hand that I need to do this experiment.

As to the grass, it's going dormant very soon. I no longer plant winter grass.

Ya know… what does it matter? This is probably a holomictic system anyway.

If there is zero increase in tds% at depth, then you are as good as the percentage of water swap. If there is some increase in tds% at depth, then you are a little bit better than good after the swap.

So, yeah. Execute the plan, suck from the bottom; nothing to lose, might actually be a winner.

(Suck from the bottom… I do not recall saying that phrase before… ever!)

This pool is probably holomictic. That is, unless this is an extremely deep pool. (What an excellent word, "holomictic." Thanks ) If this pool does develop stratified thermal layers, then I would expect algae would not form at the bottom of the pool due to a lack of infrared light.

Just a couple of thoughts...

Do you know what is in the pool besides water, and whether it is good or bad for the grass? (I assume that since you say "hardness/mineral content", you are referring to calcium.) Maybe it isn't enough to make a difference.

One problem I see is that overnight temperatures might cool the surface and cause some convection. If that is the case, it probably doesn't matter where your water inlet is or how long you wait.

The results are in! No delectable difference.

Well, there's one of the great mysteries of life in the back yard solved.

cheers

Okay, Thanks! Good to know.

Note to self: In certain conditions and circumstances, ‘suck from the bottom’ technique will yield satisfactory results.

This does NOT apply to the political kind of pool. There, you'd want to always choose top suction.

no delectable difference

So you tasted it?!

I had a facility that had a problem where the cooling towards where stainless and galvanized material. And the water supple had a high grain in it where the minerals reacted with the galvanized metals

Find out what your dealing with and get a water testing kit.

test your pool as well as you water supple and find out how many grains it is for hardness and what kind of minerals..

1.) is the water supplied by a well or is it a municipal supply.

With well water and some municipalities the problem that you may already know is that water dissolves minerals from rocks and soil as it flows through the environment, and these dissolved minerals are called Total Dissolved Solids (TDS). Common examples include calcium, magnesium, potassium, sodium, and various salts like chloride and sulfate, all depending on your geographic location. This is why tap and groundwater have different mineral compositions depending on their source, and why mineral water from natural springs contains a high concentration of these substances.

Some minerals can settle out of water, but TDS minerals generally do not. Dissolved minerals are in a liquid state and will not settle unless the water is supersaturated, at which point they precipitate out and become solid particles. Suspended solids, such as sand, silt, or other particles that are not dissolved, will settle over time and are not technically part of TDS, but can contribute to the overall sediment in a body of water.

Along with some minerals wont settle out where some minerals can create nucleation; what is called heterogeneous nucleation is a very common process where existing mineral surfaces act as the sites for new mineral crystals to form. Minerals can also form via homogeneous nucleation, where they spontaneously form from a solution, liquid, or vapor, and through non-classical nucleation, involving intermediate clusters or particles.

Very informative! Thanks.

Depending on how strong your suction pump is, once you start pumping you will introduce a swirling movement of the water so it will mix any layers you have so it won't make a difference.
Also there are some factors missing in your post; the deep end is 10', whats the shallow end ? Lenght and width of the pool. How many gallons are you going to pump out and spray over how big an area of grass?
Any minerals etc. will probably have a PPM in the millions to one !

Depending on how strong your suction pump is, once you start pumping you will introduce a swirling movement of the water so it will mix any layers you have so it won't make a difference. PUMP IS 350 GPH Not a factor. sample taken at start of flow..

Also there are some factors missing in your post; the deep end is 10', whats the shallow end ? Depth at the top, 0 feet. Lenght and width of the pool. NOT IMPORTANT TO ME. total gallons is.

How many gallons are you going to pump out and spray over how big an area of grass? NOT IMPORTANT TO ME.

Any minerals etc. will probably have a PPM in the millions to one !

Thank you all.

Too bad. We, our kids, our adopted boys, the neighbor's kids and grand kids all had great fun. Now, it's just an unused money pit.

“Too bad. We, our kids, our adopted boys, the neighbor's kids and grand kids all had great fun. Now, it's just an unused money pit.”

“It was fun while it lasted. Everyone that used it has pleasant memories they will carry with them for the rest of their lives… that alone is worth the price of admission….” So says the ‘Everyone’ that doesn’t have to perpetually shovel money into the bottomless hole in the back yard! Yeah, been there, I feel for ya brother!

“Any minerals etc. will probably have a PPM in the millions to one !”

An assumption on my part would be that the existing fill (old water) has a total dissolved solids count in the neighborhood of 2,000 to 3,000 ppm, and makeup water (new water, from domestic supply) would be a tds count of around 600 or 700 ppm.

Aeration, oxidation, filtering, more chemical dosing… none of these are mechanisms that will remove dissolved minerals from water.

I don't have any experience with pools but lots with dams of which we have many on our properties.

An observation with dams is that the top layer of water, maybe a foot or so is warm and the deeper you go the colder it becomes.

Often it will be noted that the water has an overturning of the bottom colder layer to the top as can be seen by the difference in colour in the water with clearer or striated patches.

Our dams do not become clear unless they are treated with a flocculant to remove the suspended clay but the use of Alum kills the fish and Gypsum can have an effect on the clay sealing the dam.

Can you identify the mineral content to know if it is going to be a problem on the grass?

It is still unknown what minerals are the problem.

Where I live in a dolomitic area the problem in pools are calcium + magnesium carbonates and adding a bit of rainwater from the roof does help to keep the PH neutral .

The PH of groundwater is above the capability of the pool PH tester kit.

Thanks!

If you have used an algaecide that contains copper sulfate, DO NOT DRAIN IT ONTO THE GRASS!

I made that mistake once and it took about 10 years before we could get grass to grow in that area again. If that stuff kills black algae, it will kill grass!

No CuSO4.

Thanks!