trichlor, ezpool, or salt?

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For now, I am going to work on 'learning the ecosystem' of my pool as defined by her daily consumption. She is in full sunlight all day long and the temperatures of late have been without mercy. Rain and overcast have proven absent moderators. Liquid bleach is a constant that I can easily measure the addition of and confirm the depletion of by way of testing. The Poolmath tool is GREAT! Love it. I punch in the morning reading on free chlorine and add what it suggests. This, I can understand and it settles my angst about moving forward without the pool guy who needs to sell me the latest new miracle product designed to bounce my readings and clog my filter. So far, my pool comes in slightly short of target each day but that may be the sunlight consuming more than I anticipate. I prefer slighted results as opposed to something over the top. I test and check for possible false readings that might be caused by copper, cya, and testing error. I retest every evening to get a sense of her requirements for sustainment and equilibrium . Still trying to get my husband to dump 6000k gallons to reduce the copper load (.4) and the cya level (90). My arguments are being deferred likely because of my 200 dollar water bill just to maintain the yard last month. For now though, my reads are FC 8.5, PH 7.9. TA, 110; AlkC, 83.6. CH 230, testing moderated for the presence of copper. Cya 90. Morning readings have required about 56oz of chlorine daily to sustain level. So, how am I doing? Thank you for your voices.
 
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pH is slightly high, suggest bringing it down a little.
I'm guessing AlkC is adjusted alkalinity - for PoolMath input the actual test results, adjusted alakalinity is only used for calculating CSI and even then PoolMath does the adjustment internally.

lucky lyn said:
So far, my pool comes in slightly short of target each day but that may be the sunlight consuming more than I anticipate.
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I'm not sure I understood this correctly. For CYA90, the minimum FC is 7. You should add enough bleach daily so that you never drop below 7.

Assuming 56oz of 8.25% bleach in a 18k gal pool as indicated in your signature, "Effects of adding chemicals" indicates that this equates to 2.1ppm FC daily.
The average daily FC consumption is 2-3ppm and you are within that range.

You're doing good so far but you would need to stay on top of your FC levels in order to prevent algae from growing.
 
1) We recommend using muriatic acid. Have a look at recommended pool chemicals. Use PoolMath to calculate how much you need.
2) Up to you. I'd recommend adding bleach in the evening so that the FC has more time to work without being consumed by sunlight. However, if your electric price differs according to the time of day then add it when it's cheaper to run the pump.
3) Generally, for most chemicals (bleach included), we recommend letting the pump run for 30 mins after additions. Recommended pump run times after adding chemicals are listed alongside the recommended chemicals.
 
Muratic acid lowers pH with no effect on CYA

Some like to add in the afternoon so the full effect of the chlorine is on the pool overnight with no sun loss

Run the pump 30 minutes or so to mix it up

******
On edit Abigail beat me by 3 minutes withe a great answer.
 
Thank you again everyone. Will switch to pm for adding my chlorine. Already added 28 oz this morning as my chlorine was only 7.5 with a current cya of 90 and I do not want it to drop below 7 during the day till I get the cya down. Just added 1/2 the recommended amt of the muratic acid ( about 1 cup of the 20/31.45%) to adjust the ph down. I will retest this evening and add more if necessary. Husband agreed to help me drain part of pool in the evening to reduce copper (.4) and CYA level. Current recommendation is to drop 44% but with my vinyl liner, I don't want to move fast. Will probably drop about 2 feet and retest. Plan to wait to work with calcium level ( 200) till after the rest is resolved. Would not worry about CH except I have a fiberglass spa that spills into the pool and I don't want problems with equipment. The spill will help aerate the pool and may impact my TA. Please advise if my logic train is ill advised.
 
lucky lyn said:
Thank you again everyone. Will switch to pm for adding my chlorine. Already added 28 oz this morning as my chlorine was only 7.5 with a current cya of 90 and I do not want it to drop below 7 during the day till I get the cya down. Just added 1/2 the recommended amt of the muratic acid ( about 1 cup of the 20/31.45%) to adjust the ph down. I will retest this evening and add more if necessary. Husband agreed to help me drain part of pool in the evening to reduce copper (.4) and CYA level. Current recommendation is to drop 44% but with my vinyl liner, I don't want to move fast. Will probably drop about 2 feet and retest. Plan to wait to work with calcium level ( 200) till after the rest is resolved. Would not worry about CH except I have a fiberglass spa that spills into the pool and I don't want problems with equipment. The spill will help aerate the pool and may impact my TA. Please advise if my logic train is ill advised.
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Well thought out, but aeration will affect pH, not TA. Aeration raises pH.
 
Draining question. If my pool is 18k gallons and the dimensions of my pool are 22'x33', depth on the shallow end is 42" and depth on the deep end is 8' which is news to me...thought it was 12...but reviewing the previous owners contract with the pool company for installation..... it clearly states 8 feet..hummm. Given that, I estimate that each foot of water drained would remove 726 cubic feet of water at 7.48 gallons for each cubic foot removed. So each one foot I drain will reduce my pool volume by about 5430.48 ( not counting the 500 gallon spa which I am going to ignore for now). This would be roughly 1/3 total water volume and about 2489.52 gallons less than the pool calculation tool recommended draining ( 44% total volume, 7920 gallons, based on my CYA 90% ). I do not want to damage my liner. How low do I dare allow my drain to go given a 42" depth on the shallow end? I really do not want to float or damage my liner.....even at the risk of a second required drain. Would it be acceptable to simply target a higher CYA, wait for winter to deplete some of the cya and go at it again next spring? If my math is off, please let me know. I have not worked calculations like this in ages.
 
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You can drain down to leaving one foot of water in the shallow end.

I think you are over thinking the math. No way 1 foot is 1/3 the pool. Likely closer to 1/4 or less. The average depth had to be between 4 and 5 feet.
 

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There are different ways to do it depending on how much water you need to replace and what equipment you have or are willing to buy. I wouldn't worry that much about the math as draining the water down to a foot in the shallow end will likely get you close to 50 and in Florida that might be good enough.

Like Jblizzle said, you can drain down to a foot in the shallow end and shouldn't have any problems with your liner. That would be drain then fill (separately).

There is also drain and fill doing both at the same time usually using a garden hose to introduce fresh cooler water in the bottom of the deep end while draining off from the shallow end. The weight of the cooler water helps keep it separate from the warmer water you want to get rid of.

You can also use a tarp over the pool and put water into the tarp while pumping water out form underneath the tarp.


Then again trying to figure out your math I'm not feeling so well :confused: I've done it over and over and I'm going to feel pretty silly trying to tell you it's bigger as you should know.

Rectangle, 33 feet long, 22 feet wide, 42" in the shallow end and 8' in the deep end gives me about 31K (+ spa) gallons using a number of different calculators ?? I would think if you're basing your chemicals off of a 18K volume and it is bigger that by now you would have noticed you don't hit your target.
Is it a rectangle or a freak of nature like mine ("Lazy L" in profile picture) ??
 
My pool is really odd......It looks like a lumpy kidney with a spill over fiberglass spa connected to it. The base slopes wildly. Really not impressed with the design. Shallow end is too deep and deep end is too shallow. It is classified as a non-diving pool for good reason. Even so, the designers placed a "diving rock" at the deep end. ( I put flower pots on it to discourage anyone from getting hurt.) The papers left from the folks who installed it show two design names...Lagoon Left and Calypso. In the deepest part it is 8'8". In the most shallow section it is 42 inches deep. The info on total gallons comes from the company listing 18,039 gallons in the pool and 500 in the spa. I WISH this was a rectangle. I would not bang my head so often when I try to swim and putting a screen over it would be infinitely more workable.

Used a percentage for my drain off the total pool volume of 18k. Since the pool math tool said I needed to dump 44% to adjust the CYA......I decided to approach this with care and dump 25% and adjust, then dump another 25% if need be. Figured an average depth by taking the deep end measurement and adding it to the shallow end and dividing by 2. Water level in the shallow end is really only 38". (42" includes the trim) Added 8 feet( 8.5 figure also included trim) and divided by 2 giving an average depth of 5.55, rounded to 5.6. Divided 65.5 by 4 and arrived at a 16.3 inch drain. That would leave 22 inches of water in the shallow end. Took base line readings of my pool water and tap water. Worked projections for my water balance by factoring the pool water at .75 and the fill water at .25. Added the results together for my expected change. Did not factor in the spa . Figured I would work out that difference later. Worked out well.

Numbers went like this: Pool water x .75 + tap water x .25= expected change/ final tested value this morning
chlorine 6.0 x .75 + 0 x .25= 4.5 / 7.0 see note below
note: I knew chlorine would be low so I used the anticipated reading to determine how much chlorine
to add last night after refill was complete. Math tool recommended I add 84 ounces of bleach to hit a target of 7.5.
I added 56 ounces and planned to add the rest after morning testing. Morning read was 7.0.

PH 7.7 x .75 + 7.0 x .25 = 7.5/ 7.7
added 4.8 oz muratic acid this morning to adjust down. retest 4 hours later 7.5.

TA 95 x .75 + 35 x .25= 80 / 80

CYA 90 x .75 + 0 x .25= 67.5/ 65

CH 200x.75 + 0 x .25 = 160/160
Will adjust up to 250 because of the fiberglass spa and equipment

Copper .4 x .75 + 0x .25 = .3/? can't test directly for this but my calcium hardness test
did not require the usual 6 drops of reagent to see my result.

Took sample to pool store this afternoon when I went to replace some of my testing materials. They used a machine to read data. Most of their numbers were fairly close to mine with the exception of my chlorine read.
Figured it may have something to do with my need to use the 2005 kit because I was out of the FAS-DPD titrating reagent and the 40 minutes the sample spent in the car. Bought some more Reagent and ran my test when I got home. My reading was higher than theirs. I used the 2ppm factor and at 27 drops ( 5.4) my solution was still clearly pink. No shift till 28 and it was even brighter at 29.

The sample read out from the pool store was as follows:
free chlorine 5.41
total chlorine 5.41
combined chlorine 0
ph 7.7
Hardness 167
Alkalinity 77
CYA 64
Copper .2
Iron .1 ( never had this before)
Borate 0
Saturation index -0.27


So far, I figure I need to add 39 oz of bleach, 4 oz of acid, 14 lbs of calcium chloride, dump 22% of my water next weekend or wait out the winter with this level. Tonight we will open the valves for the skimmers and the spa , add my needed chlorine and retest in the morning to get a handle on how much more calcium and I need. Your thoughts are appreciated. Thanks for crunching the numbers.

If you don't mind, I would like to seek some advice. In may , my calcium hardness was off the page from the EZpool build up. The hardness reading was 600. My cya was 99, my TA was 0, and my ph was 7.0. TDS was 475 and phosphates were 300........thank you EZ pool. My spa developed a leak from the light fixture. Took a couple weeks to get someone in to help fix it. Dumped tons of water and adjusted my numbers a bit at a time and switched pool over to trichlor tabs which then raised my cya level back to 90. Went to straight bleach. Things looked good. Light came loose from its attachment again in July, no signs of leakage, and we had someone come fix it again. Asked the tech if there was water in the light and he said he did not recall any. Is this light safe or should I have them pull it out and put a new one in. There is a lot of staining around where the light sits in the spa wall. Any recommendations?
appreciate the help, lyn
 
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lucky lyn said:
Long term, I am thinking that I can use the Tri chlor once the value of my CYA drops to 50 and then go on a 'tab holiday' when it starts to rise and use the liquid chlorine.
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50 is already at the high end for CYA, and using tabs would cause it to go even higher. If you had a CYA of 30, I would say you could use tabs for a bit longer, or for maintaining FC while you are on vacation, but if you are at 50, you'd already be at the high end.

Regarding SWG, I would fill my pool in if I didn't have an SWG. Pretty strong words, huh?
 
Sounds like I need to do the next dump to get down to 50. I kind of like the idea of reserving the tabs for when I take a trip. Your reference to 'filling your pool' if you did not have a salt system is consistent with what I have heard. My husband hates this pool....and the yard....and the house. I lived in Arizona when my husband was stationed there twice. On the first tour there, we had a pool and it was wonderful for me..not so much for him and the annual acid bath it required out there resulted in us avoiding a pool for the second tour. I really missed it. When he took a job here in Florida, I insisted on a pool. He agreed with great reluctance. That is why I have tried to take it over. This has been a steep learning curve. He is still better with the machinery than I am, hence my insecurity with playing with the valves. A salt system is on my wish list. Sounds like it is worth saving for. Thanks for taking the time to respond. lyn
 
I forgot to mention, given your CYA of 90, if you install a SWG, you could leave it at 90 and not have to drain at all.

You should be able to get a SWG for your pool for under $700. I did a little looking and found one for a 40,000 gallon pool for $659. Keep that in mind too, you want to oversize the system for your pool.
 

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