Pool water drain and replace during a drought

This is my first of soon to be many posts to the forum. I have been servicing my pool for 14 trouble free years until about a three months ago. I have been relying on my pool supply store to do most of the water testing. I would do simple chlorine and PH testing a couple of times a week using a very simple taylor kit. I have been using the 3" free floating tabs since pool was opened in 2000 and shocking (SLAMMING) weekly during the swim season. I have religiously cleaned the filter cartridges anytime I had a back pressure change of 8 psi. I replace the cartridges every 4 years. I use a Poly 60 algicide for routine maintenance. I filter the pool year round 10 hours and day cleaning the pool skimmer, pump strainer and suction inline strainer every Saturday morning. About three month ago I noticed my FC level was almost zero. I increased the openings of the free floater holding the 3" tabs to increase the chlorine level and added 2 lbs of shock. the FC level two days later was again almost zero. Took a water sample to my regular pool supply store for checking and was told I needed to add 10 lbs of a chemical to balance the the water. PH was 7.4 and FC and CC was zero. I now had started to develop a very small amount of green algae. I added a second free floater of 3" tabs to try and increase the FC levels. I now had 10 3" tabs slowly dissolving into the pool with no increase in the FC. PH was stating to drop (7.0) so I added 5 lbs of PH plus. By this time I had started to develop a pink algae in a couple of small places by the steps. Went back to the pool store and was sold a product called "Pink Treat". Applied this product as instructed and all traces of the "Pink Algae"are gone. At this point in the story I decided to do some internet searching for my FC problem and pink algae problem. I came upon TFP and found a wealth of information. I have learned about you guessed it "CYA levels". I also learned about "Sodium Bromide". Based upon the TFP recommendations I ordered a Taylor 2006 test kit and decided to do more extensive testing than just FC and PH. here are the test results taken this morning after adding 1 gallon of Walmart 8% chlorine the night before. FC=1.5, CC=1.5, PH=7.4, TA=200, CH=375, CYA off the chart but it was 200+. At this point it is very clear to me that I need to drain the pool. This leads me to the title of this post. Does anyone know the legalities of asking for an exemption due to health concerns of the state of the pool water draining and adding 12000-14000 gallons of bad water to the city sewer and drawing the same in fresh water. I really hate to use my pool supply store as I feel they should have caught the CYA and TA levels. I am going to a different pool supply today to try and get some answers. Any suggestions on limiting the damage to the pool at this point?
 
I'm a little new so I'm not 100% up to speed yet. But, there are several threads that talk about a partial drain and refill. Where they will pump from the deep end and fill in the shallow end at the same time. It usually takes a few of these to equate to a full dump and refill. Search for those threads, or I'm sure someone will come along and knows a tad more.

I don't know about CA, but around here there are no concerns about draining. The real concern is our water restrictions. If we get to stage four, they do not allow for draining pools. At that point, I guess you'd have to drain and truck in water or do some type of RO treatment to the pool water.
 
Hey Papahemi, down in Orange County, there are no restrictions in draining and filling a pool (yet). The cost is covered in the fill cost of the water bill. I wouldn't do a pump and fill at the same time. From what I know of how this works, you will use less water overall if you do one big dump rather than a lot of small dumps (dumping half will leave half the original chemicals, but dumping down to 75% twice will only get you down to 56.25%, but use the same amount of water).

There is a potential a large dump and refill can harm the pool from what I understand. I think a lot of that depends on your ground water levels (which I wouldn't think would be an issue with the drought). I personally dumped 50% and then 75% with no noticeable issue.
 
If you've been using pucks for a while, you probably have an empty 5 gal tub around. If you do, I would use it to try to gauge your CYA level a little better. Rinse it out and use the bucket to create a 3:1 solution of pool water. This 25% solution ought to allow you test your pool water CYA up to 360 ppm by multiplying the read value (20-90) by 4. Add 1 qt pool water and 3 qt tap water (tap water has no CYA), stir and let stand for 30 minutes. Then run a CYA only test to see if you can get a reading below 360. This will give you an indication of how much water you need to drain. If you can leave enough water behind to retain 40-50 ppm CYA, you wont have to put back into the pool as I think you are already planning.

There are also links associated with vinyl pool water replacement, where they use a tarp or cover to create a fill water zone on top of the water being drained. This alternate drain/refill method can allow you to do the drain while not co-mingling the water, and provide the protection you desire to prevent damage to your pool. This method will virtually prevent dilution of the drain water with fresh, that would cause you to have to drain even more than the 14000 gallons you are estimating.
 
An easier way is just to dilute your test sample in half and it will be more accurate. You will not be that accurate trying to test up to 360 PPM and it's honestly pointless. If you have to more than double the Cya test sample you are way too high anyway.

Drain and refill partially is simpler too. If you are worried about issues with this, do a 1/4th or 1/3 at a time. As with all things and our philosophy... Keep it simple as possible.
 
There may be another option.
It seems that most places that have water shortage issues, there's someone offering reverse osmosis services. Here in Tucson AZ you can get them to bring a machine and let it run in your pool for a couple days. It can pull out all the CYA and calcium. Runs about $400 here and you still lose 10-20% of the water.

-Denny
 
5 gallon bucket for a test sample? 5-10 ozs of pool water would be more than enough! I do agree with the 3-1 dilution technique though! Yes, a 1 to 1 is more accurate, but you don't need accuracy as much as you need Ballpark figure for your cya level to determine about how many times you will need to do the partial drains and refills so you won't feel the need to do a whole bunch of retests. That way you should only need to retest once you get to what should be < 90 but still over 50.
When I had to go through the process, I did 5 1/3 drains and refills to get mine to 50.
 
There may be another option.
It seems that most places that have water shortage issues, there's someone offering reverse osmosis services. Here in Tucson AZ you can get them to bring a machine and let it run in your pool for a couple days. It can pull out all the CYA and calcium. Runs about $400 here and you still lose 10-20% of the water.
-Denny

I think OP mentions that the nearest one is 350 miles away. Great option if you have it, but there are precious few of these services out there.
 
Jason, that's the first time I've seen accuracy codified with a number. When I was trying to discover my true cya level last year, I had to do multiple cya tests using up a lot of the r-0013 reagent filling to the 7ml line of the mixing bottle diluting to the 14ml line then dumping back to the 7ml line. After multiple performance of that process twice to be more precise, I finally got a test to show a result of ~90 multiplying that by 4 my real cya level was ~ 350. That turned out to be pretty accurate as after each 33% drain and refill, I'd retest and the reduce the dilution factor each time as needed. Each new drain and refill became more accurate as the process went forward. Truthfully I overshot my goal of 50ppm on the last one. If I had done a single test of 3 parts tap to 1 part pool, I'd have saved about 28ml of reagent and a whole bunch of time and the gas to go to leslies to get another bottle of reagent. Less accurate is probably correct, but in my experience +- 80 wasn't.
 

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I want to thank everyone for the thoughtful and educational comments. I have decided that due to the pressing need to replace the water by draining and refilling I will go ahead and do the pool resurfacing 2-4 years ahead of schedule. I have been battling a minor pink algae because of the very low chlorine levels. After trying the "Pink Treat" and continuously adding liquid chlorine (two gallons every night) I have kept it pretty much in check. Starting tomorrow the Pool Plaster company will arrive to drain this chemical quagmire and start removing the white plaster and tiles. The city doesn't care along as the chlorine level is zero and its classified a "Pool repair" and you pay a $40.00 fee. We are now in a Stage 2 drought situation. If we go to stage 3 I can forget about changing the water. So its now or maybe never. We have decided to go with a product called "Stonescape mini pebble" and new NPT tile. We are also replacing the silicone sealant between the bullnose brick and the cement deck. I have also ordered new cartridge filters for the Clean and Clear along with a o-ring rebuild set. I will post before and after when construction is complete. Again thanks to everyone.
 
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