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CoolRaul

CoolRaul

0
Jul 8, 2016
20
Woodland Hills, CA
Hi,

Purchased a home with nice pool ~8 yrs ago. Have a pool maintenance person (PM) maintaining pool however lately he has allegedly been experiencing quite a bit of trouble with the pool Seeking expertise of this board. HELP! Thanks.

For the last year my pool matainenance person has been complaining that there is zero chlorine in the pool when he checks it nearly each week. He has no answers to provide. Just repeating that someone must be peeing in the pool - "Does the gardener bring his children to swim and pee in the pool?" ,"Are my neighbors jumping the fence and .......", well you get the idea.

I have a wife and son (15 yr old...the son, not the wife). Extremely rarely do either of them swim. I swim 1-2 per week. I asked PM about sweat, fertilizer runoff from potted pants, etc.... Same answer - "gotta shock it with granular". Dumps it in and then see him next week only to say the same thing. Chose to do some research and found this site.

Thought for sure I'd SLAM the pool to ensure we kill anything and get a good amount of FC in there for a sustained period of time. Per my signature, have a ~18,000 gal pool. Threw in 2 gallons of 8.25 bleach on Thursday afternoon. Water got a little cloudy and tiny bit yellow/brown. (Only have a very old Taylor (10yr+) kit I found from previous home owner. Basically brand new. He never used it.) I "inherited" the PM. Went online per good advise here and ordered a K-2006 FAS/DPD). Meantime tested FC w/ old kit and it must have read about a 15ppm (kit doesn't go that high). Stayed that way all day. Next morning it looked just a shade lighter. Still high. Threw in another 1/2 gal early in the morning. Stayed relatively dark on the scale all weekend long. Added no more bleach.

Today, Monday my new kit arrived. Test revealed ~9ppm FC and 0.5ppm CC. Also indicated a high calcium level (quite cloudy test sample during FC test - learned this on youtube video). Figured the FC is still too high to test for any other parameters so stopped there. Need it to come down naturally first.

So why does the PM maintain that the pool registers zero FC nearly every week, even after shocking it, when clearly the FC seems to have some good staying power during my SLAM? Overnight seems good. Daytime seems good. Maybe the only thing that he is shocking is me with his bi-weekly shocking charge? What is the proper range for FC in my size pool? 1-3? or 3-7? Pool is a bit shallow and weather is quite hot here so pool temp remains rather high year round.

So, am I on the right path to solving this dilemma? Perhaps I should be doing this myself if once it is set, it is easy to maintain. Don't think he's ever changed or drained any water from the pool in the 8 years I've lived here now. Does it need to be refreshed periodically? It certainly evaporates a lot. may the cause for the high calcium levels?? Pool had a black bottom at one time but now is mostly mottled with very little black. Don't know if that is due to Calcium or other things.

Thanks for your time.

Ray
 
  • FC - Free Chlorine - ~9ppm
  • CC - 0.5ppm
  • PH - Acidity/Alkalinity - 7.3 (needed to add 3 drops to get to 7.4)
  • TA - Total Alkalinity - 350ppm ( " " 35 red)*
  • CH - Calcium Hardness - 600ppm ( " " 60 )*
  • CYA - Cyanuric Acid - only needed 1.6ml to completely obscure black dot so must in in the 200 range). wasn't aware of the further dilution method with tap water. Will get more accurate reading tomorrow however for now it appears "off the charts".
*now know to go to 10ml to save reagent volume. Learning process I guess.

More tomorrow.

thanks.
 
Sounds like you have a good understanding from doing Pool School here, and I suspect you know what you're facing. Sorry to hear what the poolie did to your pool :(

It's a bit of work at the beginning to adopt TFPC, can't kid you about that. After it's sorted out, it's very easy to keep it running well, and you'll have spectacular water.

Let us know your plan, and we can fill in gaps or mention tips to make it easier, if need be.
 
Dilution test is easy. Just collect a certain amount of pool water. Add to that the same amount of tap water. Use the combined water as pool water for the test. Then double the value you get when the dot is no longer visible.
 

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Well, due to the high CYA and CH, the ole' PoolMath cites I need to replace 2/3 of the pool water (12,000 gallons!!). Whew! That's tough in SoCal! Then I guess once that's done just retake all the readings and start again from there (rinse/repeat). I think I asked earlier, but anyone have any idea as to how often pool water normally needs to be changed? Hard water out here. I'm guessing 8 years is a long time without a water swap???

Many thanks again for all the kind assistance.
 
pooldv said:
Pool School - Extended Test Kit Directions
Click to expand...
+1 and click through on CYA test and see #9

Exchange water in the pool only to reduce the CYA level. With TFPC, you'll be able to manage for your CH level quite handily.

Frequency of refilling due to accumulated CYA is dependent on the amount of splashout/backwash vs. the amount of CYA going in. It's quite hard to a frequency of water exchange, although with TFPC methods, water exchange might not be needed at all.
 
CoolRaul said:
Well, due to the high CYA and CH, the ole' PoolMath cites I need to replace 2/3 of the pool water (12,000 gallons!!). Whew! That's tough in SoCal! Then I guess once that's done just retake all the readings and start again from there (rinse/repeat). I think I asked earlier, but anyone have any idea as to how often pool water normally needs to be changed? Hard water out here. I'm guessing 8 years is a long time without a water swap???

Many thanks again for all the kind assistance.
Click to expand...

If you're not in a hurry you can reduce CYA level the same way I did- by completely switching to liquid chlorine (bleach). It took time, in my case- more than a year to drop it to recommended level. This happens due to water loss during filter backwash so when you top up your pool with city water which doesn't have CYA it eventually gets lower. We had few heavy rains last year so if you time it right you can drain 1-2 inches of water and the rain will refill it back. You'd also need to maintain higher FC level throughout, mine was in 12-15 ppm range all this time.

Another related problem is high hardness of the water in your pool. I still have 500ppm and city water is 170. Due to evaporation it's getting worse over time. I'm planning to install water softener and use that to replace water, should take care of CH the same way it did for CYA.

Since all above sounds like a hassle you could try RO mobile service. While it costs hundreds I believe it's still cheaper than replacement and it would take care of both problems (CYA & CH) at the same time.
 
Reverse osmosis is an effective option at around $500 plus. It's worth checking the water cost or penalty in comparison.

The cloudiness and color you mentioned in your first post suggest you have an algae bloom going on in your pool. You can do an overnight chlorine loss test to find out for sure.
Pool School - Perform the Overnight FC Loss Test (OCLT)

It's true that everything can be done at high CYA but it may not be practical, especially if a SLAM is called for. Looking forward to hearing the result from your diluted CYA test.
 
It would be time to change water for me, but only because there's an algae problem. Water exchange is a big thing to do, and it's true that you can sanitize the pool 12-16 PPM FC and be safe. So I would do the OCLT first. It's quick and easy.

It's also true that you could SLAM using 64 ppm FC as the shock level, but that's the impractical part. The initial charge might be do-able, but during a SLAM you lose FC faster to the algae obviously, but also because CYA's ability to buffer is over-whelmed. So the re-charges are also higher, but potentially not as much higher as the initial charge.

It's fair to mention that the test result is less reliable due to the dilution as well.

I followed another thread using cold fresh water at the bottom (circulation off of course), and removing the CYA laden water from the top. The person reported good success, but the method has been less successful for others. It seems like a summer option, because the colder more dense water will stay at the bottom, and CYA does not diffuse particularly well. But working against the method is that the pool water with higher dissolved solids is more dense than the fresh water. So I suppose the method relies on a big enough difference in temperature between the pool water and the tap water.

Drain/refill for the full amount would be the most reliable/predictable, provided water table and upward hydraulic pressure on the pool shell is not an issue. (probably sounds stupid mentioning this for your location!)
 
Well, I can run the OCLT test tonight however I'm rather certain that the FC has been rather stable. Water is crystal clear. It's just that the CYA and the CH is so darn high. With the FC so stable after dumping 2 gals of bleach in there nearly a week ago, that's why I cannot understand why my pool guy kept telling me pool doesn't hold the chlorine he says he keeps putting in there.
 

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