First time using Pro Test Kit, Calcium Hardness very high.

[ttlkurtis]

Hello everyone! Hoping a newbie can get some help with next steps. It's been a few weeks since we fired our pool cleaning company, they would occasionally no-show, I don't think they were taking any measurements and just threw a fixed amount of 'shock' in the pool every single week. I was a little slow on figuring out next steps before deciding on the TF Pro Test Kit, and here we are now. After running all the tests for the first time, this is what I've got below. Given the CH and CYA recommended actions, I assume the best course of action is to FIRST drain most of my pool water and then re-fill it, correct? Then redo the tests and see what the recommendations are at that point to re-open the pool basically?


Current CH: 1,000 / Target CH: 450
Calcium hardness level of replacement water in San Antonio, TX is 175 as measured from my tap (357 according to the internets, generally in my city).
Recommends replacing 86% by volume of pool's water to reach target.

Free Chlorine
100 CYA
Current Free Chlorine: 7 / Target Free Chlorine: 11
7.5% Bleach 121oz bottles... recommend adding 144oz by volume to reach target.

pH
Current pH: 8.2 / Target pH: 7.6
Current Total Alkalinity: 170
Muriatic Acid 31.45% - 20* Baume
Add 49 oz by volume to reach target.

Total Alkalinity
Current TA: 170 / Target TA: 70
To lower TA you reduce pH to 7.0-7.2 with acid and then aerate to increase pH
** Aerate? Like... pump on high for a while?

CYA
Current CYA: 100 / Target CYA: 45
There is no chemical to lower CYA levels .Draining some water and refilling can help lower CYA.

 

[HermanTX]

Welcome to TFP.
Thanks for the details of your first test.
I question if your CH is actually a 1000ppm. This test requires a 10ml sample and each drop is valued at 25 so a 1000 would be 40 drops. It is worth doing the test over again. I see your tap water is 350 ppm so you would have had to add lots of water or the pool service was using Cal-Hypo to shock your pool.
Did you test the CH of your tap water or use a government report? Best to test that yourself as well.

You are correct that both CH and CYA can only be reduced by draining.
Ensure that you drain and start filling immediately and try to do on an overcast day to avoid the sun beating down on the plaster.

Your TA will come down in time - it is not an overnight result by using MA and aeration. What is the TA of your tap water? When you drain that will be affected as well.

I would adjust FC and pH now only if you plan to delay the drain process until an overcast day.

 

[ttlkurtis]

Welcome to TFP.
Thanks for the details of your first test.
I question if your CH is actually a 1000ppm. This test requires a 10ml sample and each drop is valued at 25 so a 1000 would be 40 drops. It is worth doing the test over again. I see your tap water is 350 ppm so you would have had to add lots of water or the pool service was using Cal-Hypo to shock your pool.
Did you test the CH of your tap water or use a government report? Best to test that yourself as well.

You are correct that both CH and CYA can only be reduced by draining.
Ensure that you drain and start filling immediately and try to do on an overcast day to avoid the sun beating down on the plaster.

Your TA will come down in time - it is not an overnight result by using MA and aeration. What is the TA of your tap water? When you drain that will be affected as well.

I would adjust FC and pH now only if you plan to delay the drain process until an overcast day.

This whole week is overcast, so that's actually perfect... It did in fact take me 40 drops for that test. I am pretty sure our pool techs (it was a different person every week it seemed) had no clue what they were doing. They had to ask me how to turn the pump on to circulate the chemicals they added one time recently. It wasn't long after that I decided to fire them and do it all myself. Looking at my security footage in the back yard, I never saw them measure anything, just broadcasted the same thing over the pool every week it seemed.

I don't know specifically what they were using, though.

When you say I would have to add lots of water, I'm not sure what you mean. All of the pool water was from the garden hose, we didn't have a water delivery service pump in water when we opened the pool or anything like that. As for the tap hardness, I'm going by the city rating, but I can confirm that with a test.

 

[ttlkurtis]

Just tested the tap water with the kit, and it comes back with a CH level of 175, which now recommends replacing 67% of the pool water. That's definitely better than 86%.

 

[HermanTX]

Just tested the tap water with the kit, and it comes back with a CH level of 175, which now recommends replacing 67% of the pool water. That's definitely better than 86%.

Great - dd you also test TA for the tap water?

 

[HermanTX]

When you say I would have to add lots of water, I'm not sure what you mean.

CH can only increase if you add the chemical or if the tap was was extremely high and you kept topping off your pool due to evaporation This would build over time and cause your CH to be extremely high. My guess is that now that you confirmed your tap water is 175 then the pool service was most likely adding a lot of Cal-Hypo as shock. This would increase your CH over time.

 

[ttlkurtis]

Great - dd you also test TA for the tap water?

Now I did: Tap water TA is 170.

 

[an1vrsy]

Great job getting the TF-Pro. One thing to keep in mind about testing for TA when the kit is new. The TA test reagent, R-0009 can have a static charge on the tip. This static causes the drops to not fully form, which skews the test high.

So try this when testing TA for now, use a damp not wet tissue and wipe the tip between each drop. This will lesson any effect and yield a more accurate TA test result.

 

[ttlkurtis]

Great job getting the TF-Pro. One thing to keep in mind about testing for TA when the kit is new. The TA test reagent, R-0009 can have a static charge on the tip. This static causes the drops to not fully form, which skews the test high.

So try this when testing TA for now, use a damp not wet tissue and wipe the tip between each drop. This will lesson any effect and yield a more accurate TA test result.

Thanks for explaining the wiping the tip thing. I did follow the instructions and do that, but I had no idea -why- I was doing it. Now I know!