need help in chemistry and leak problems

Oct 24, 2017
57
Branchburg, NJ
Hi everyone,
I just finish my pool retaining wall. so I hook up my new Jacuzzi pump (new) fired it up and there are few things that I see not quite right.

open the pool cover, I can see the pool bottom. First time ever open the poo cover and see the bottom (i bought the house last April and the pool was dark that I barely see the light at the end of the pool when take the cover off). GOOD SIGHT
Anyway, below are my chemistry test results after the pump ran for 2 mins :)

FC: 0.5
pH: 6.8
TA: 30
CH: 0
CYA: 20
Temperature: avg. 55F
I plan to test water again tomorrow morning before adjust the chemistry.
my question: should I adjust my chemistry to the level recommend by the PoolMath Apps before I Shock the pool? Do the PoolMath has instruction somewhere on how to use the software?


thank you for your time that read my lengthy post and helping me.
Olivier
 
Olivier, you will need to adjust some things before starting a TFP "SLAM" (link below). Your pH is a bit low, so is your TA. Give the water about 30 min to mix really well before grabbing a sample tomorrow. If the TA and pH are both still low, raise the TA to about 50 for now, and the pH to at least 7.0. The CYA needs to be increased to at least 30 so you can raise the FC to "12" which would be a good SLAM/Shock level. Use items from the TFP Pool School - Recommended Pool Chemicals page.


Question - Your sig shows fiberglass steps. What about the rest of the pool? I'm assuming vinyl? Just want to make sure since your CH is showing as zero.
 
the step is fiberglass but the pool wall is lined with vinyl.

last night i add soda ash 4lbs to raise my ph.
my latest parameters are

FC: 8.0
pH: 7.6
TA: 170
CH: 275
CYA: 100

is this normal or something wrong? my niece test it last night and this morning.
Pump running since 3pm yesterday in re-circulation non filter mode (setting with multiport valve).
 
I suspect there may some testing errors in one of the sets of results above. I say that because your first test showed a CYA of 20, but the next one 100. Unless you added a lot of stabilizer overnight, there's no way CYA would increase like that. I also question the TA test as it would take a lot baking soda to increase it that high.

So before you do anything more, lets back-up and confirm a few things before we go any further:
1 - Are you sure your pool is 40,000 gallons as noted in your signature? 20x40 would have to be on average 6.5 feet deep. I as curious.
2 - The CYA test is most important right now. Nothing else should be done unless we know for sure if it's 20, 100 or something in between. So I would like for you to perform a CYA test again, but follow these notes carefully:
CYA Testing:
Proper lighting is critical for the CYA test, so you want to test for CYA outside on a bright sunny day. Taylor recommends standing outside with your back to the sun and the view tube in the shade of your body. Use the mixing bottle to combine/gently mix the required amounts of pool water and R-0013 reagent, let sit for 30 seconds, then gently mix again. Then, while holding the skinny tube with the black dot at waist level, begin squirting the mixed solution into the skinny tube. Watch the black dot until it completely disappears. If it helps, pour a little, look away, then look back and pour some more. Once it disappears, record the CYA reading. After the first test, you can pour the mixed solution from the skinny view tube back to the mixing bottle, shake, and do the same test a second, third, or fourth time to instill consistency in your technique, become more comfortable with the testing, and validate the CYA reading.
Please confirm the CYA and report back with your result. Ask for a 2nd or 3rd person's view as well if you need to. Compare results.

- - - Updated - - -

Part of the problem between the two sets of tests might be that you mentioned for the first test the pump was only on for about 2 minutes. You always want the water to circulate for about 30 minutes before grabbing a water sample. So the first test might be very flawed, but we'll see how your next set of numbers look.
 
@Texas Splash, I completely concur with you about the CYA test that look weird. I retest it myself last night and these are the results

FC: 11.5
pH: 7.5
TA: 120
CYA: N/T

I confirm that the pool is 20x40 so estimate wise, 38000 to 40000 (at 4ft deep from shallow end and gradually going down to 8ft deep at the 2 main drains). I also have in hand the layout and the work order that previous owner kept. blueprint and all.
I will test again when I get home today from work with full set of info and use it as my baseline. like the old say, you want to do it right you gotta do it yourself.

I did add 4 lbs of soda ash after the first test set. the recommended amount by PoolMath apps is 5lbs but I figure I just want to do it less.

thank you for your help .
 
Okay, so now we seem to have a better pattern of testing. We know you need to SLAM. For a SLAM you have two options, and it's totally up to you:
NOTE- Both options require the pH to be lowered to about 7.2 before starting the actual SLAM.

Opt 1 - Lower pH now (to 7.2) and increase the FC to "35". It may seem like a lot of chlorine, and in a way it is, but that's because your CYA is still so high so it has to compensate. You can see that on the Pool School - Chlorine / CYA Chart.

Opt 2 - Exchange some water to lower the CYA first. Get it down to about 40 or so (changing half the water). Once the CYA is lower, THEN also lower the pH to 7.2. Finally, with a CYA of 40, your SLAM FC level will only need to be "16", so less bleach. Exchanging that water might also help speed up the SLAM a bit.

Either option is fine, but you need to decide which option your prefer. Think it over and let me know. I'll be glad to coach you through either one. Actually, besides the difference in bleach, the SLAM process is exactly the same (link below). :)

- - - Updated - - -

As a reminder - Now that you are testing your own water and learning about pool products, the CYA should never go up again like it did before unless YOU want it to. In most cases, the CYA was extremely high because owners didn't realize those pool store tablets or bags of shock contained stabilizer (CYA). Once it's in - it's in unless you change some water.
 
@ Texas Splash,
thank you very much for helping. I am planning to vacuum my pool today after work (if time permitted) and that will lowering the water. I then add water back in and test again to make sure everything fall into place then I will SLAM it.
 
I vacuumed my pool yesterday and drained out the water below the skimmer box. Filled up the pool and circulate the water for about 1 hour. the test results are
FC: 12
pH: 7.0
TA: 110
CYA: 80

my plan is shock the pool while I shock the pool, I will brush and clean the wall and vacuum out water. refill the pool again also maintain the FC level according to the CYA amount.
is this possible or I have to drain the pool until the CYA level drop to 30, then shock? It will take 2 days to drain and fill the pool and my well pump may die :(
 
You can "SLAM" with a higher FC level based on your new CYA. As you exchange more water, just be mindful some of those chemicals will go down the drain and your FC will also need to be changed. Monitor and adjust as best as you can until you have the CYA where you want it. You don't have to go all the way down to 30. Even 40-50 is fine. But once you get there, maintain the corresponding FC and SLAM until you pass the 3 criteria. That's key. Good luck!
 

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I SLAM the pool this sunday. the NJ weather is heavy cloudy with on/off rain. same with monday (today). the FC test is latest. dosing at 3pm and at 5pm tested. Skimmer/filter running, pump running at 3000rpm with DE filter pressure gauge showed 10PSI. running for 5 hours then back to 2000rpm with filter pressure gauge showed 5psi. I will report back at 4:15pm after get back from work

FC: 35 (pool math suggested)
pH: 8.4 (after added 12% bleach)
TA: 120
CYA: 75

side note of why I SLAM at high CYA. I plan to convert to Salt so CYA at 70 is good
 
Hang in there and try to stay consistent with the required FC level. No need to test anything else other than perhaps CC once you get close to passing. Just make sure to brush each day and inspect absolutely anything that can hold water or algae in the pool. Leave nothing to chance. The chlorine will eventually kill all the algae. Once the water is really clear and FC drops begin to slow down, then you might start thinking about an overnight (OCLT) test. But for now, maintain. :)
Pool School - Perform the Overnight FC Loss Test (OCLT)
 
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