Help me keep my pool clear!

zimdogg

Bronze Supporter
May 24, 2022
155
Kansas City
Pool Size
12500
Surface
Plaster
Chlorine
Liquid Chlorine
Looking to be a TFP convert. Not sure I can convert if I haven't been pool stored yet, but I'm looking to start my pool journey trouble free so here I am. I purchased the Taylor K2005 test and a supplemental FAS DPD test to go along with it. Our pool was opened a little over a month ago professionally, and the pool went from an algae infested monster to clear and swimming in about 36 hours.

First chemical test with the Taylor kit came back today. Here are results:

FC - 2.5
CC - 0 (I think, it didn't change colors at all)
pH - 7.4
TA - 90
CH - 230
CYA - >100 (see pic below)

All I've used are chlorine Tabs so far. It's been nice and clear since the pool guy opened the pool. I skim it, I use our robot, I empty the pump/skimmer baskets, etc.

So, what now? I have a Menards close for liquid chlorine, but what else should be on my shopping list? I have a picture of my current arsenal attached. Look forward to getting schooled.

Edited to add - This is not a new pool, this is a new house for my family, so the pools been here a bit. Previous owner left all the goods in the buckets from my pic in the attachment for me.
 

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You're #1 issue right now is that high CYA. Since it's over 100 you need to know about how much over 100 it really is. I would recommend running a diluted CYA test as noted in the link below starting at Step #8. That will be your first action. Let us know what you get.

 
While you're at it, I would raise the FC to at least 8 ppm using only liquid chlorine. The tabs are responsible for raising your CYA that high. With CYA over 100, you're just begging for algae with your FC that low.

Normal target for FC is 7.5 - 10% of CYA, and during a SLAM up to 40%. It is still safe to swim at that level.
 
You're #1 issue right now is that high CYA. Since it's over 100 you need to know about how much over 100 it really is. I would recommend running a diluted CYA test as noted in the link below starting at Step #8. That will be your first action. Let us know what you get.

Alrighty, I'll do that once I get home this evening.
 
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While you're at it, I would raise the FC to at least 8 ppm using only liquid chlorine. The tabs are responsible for raising your CYA that high. With CYA over 100, you're just begging for algae with your FC that low.

Normal target for FC is 7.5 - 10% of CYA, and during a SLAM up to 40%. It is still safe to swim at that level.

Sorry, this stuff is new to me. FC needs to be brought up, I understand that part. My pool math app is telling me to add 1 gallon and 2 cups to the pool to bring it up to 9.0-15ppm. That seems like a lot of chlorine. I've read others having to drain the pool a lot to get CYA down, is that the only path or does CYA ever come down naturally once you get the right FC levels in there?

When do things become unsafe to swim in?
 
Sorry, this stuff is new to me. FC needs to be brought up, I understand that part. My pool math app is telling me to add 1 gallon and 2 cups to the pool to bring it up to 9.0-15ppm. That seems like a lot of chlorine. I've read others having to drain the pool a lot to get CYA down, is that the only path or does CYA ever come down naturally once you get the right FC levels in there?

When do things become unsafe to swim in?
I don't see the size of your pool listed, but one to two gallons of chlorine is not unreasonable. I've often added 2 gallons at a time. Remember, you need to enter the concentration of the chlorine in pool math as well. It can vary anywhere from 6% to 12.5% depending upon the brand.

CYA degrades very slowly, maybe 3 ppm per month. Draining or reverse osmosis filtration are the only methods of reducing it quickly. There was some snake oil being sold a couple of years ago that purported to lower CYA, but testing amongst the members here proved it to be ineffective.

As you're learning, high CYA requires a large amount of chlorine to keep your pool sanitary. It can be done up to a certain level, but anything over 100 becomes impractical because this requires FC over 10 ppm, and at that point you can no longer reliably measure pH because the high level of FC skews the pH reading.

It's generally safe to swim anytime the following conditions are met:

- FC is at or below 40% of CYA
- pH is between 7 and 8
- You can see the bottom of the pool at the deepest point.
 
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Sorry, this stuff is new to me. FC needs to be brought up, I understand that part. My pool math app is telling me to add 1 gallon and 2 cups to the pool to bring it up to 9.0-15ppm. That seems like a lot of chlorine. I've read others having to drain the pool a lot to get CYA down, is that the only path or does CYA ever come down naturally once you get the right FC levels in there?

When do things become unsafe to swim in?
CYA can degrade over time but it's typically very minimal. 5-10ppm CYA loss every month or two levels.

We need to know what your CYA is. I've heard of people around 100 just keeping an elevated FC level until their CYA slowly degrades and is diluted via splash-out or backwashes, but if it's much higher it's going to become not very feasible to do. Try the diluted test and see where the dot disappears with a 1:1 mix of pool water and tap water at the starting point, then multiply by 2 to get the result.
 
Thanks everyone, I'll get a good reading on CYA this evening when I'm home. In the meantime going to swing by Menards and grab some chlorine.

To the person who asked about my pool size, it's 12.5k gallons (what I'm told from the previous owners, I need to calculate for myself though). It's a freeform pool, 5ish feet at it's deepest point in the middle, and has some shallow ledges around the edges too. Hard pool to measure accurately.

I'm assuming at this point, chlorine should be added via liquid chlorine and no longer use the tabs? I'll shut the chlorinator down tonight as well, but right now my pump is off so it shouldn't be circulating more.
 
I'm assuming at this point, chlorine should be added via liquid chlorine and no longer use the tabs? I'll shut the chlorinator down tonight as well, but right now my pump is off so it shouldn't be circulating more.
Absolutely. The tabs will just add more CYA and are likely why you have so much in the pool to begin with.
 

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I'm assuming at this point, chlorine should be added via liquid chlorine and no longer use the tabs? I'll shut the chlorinator down tonight as well, but right now my pump is off so it shouldn't be circulating more.
Correct. Tabs can still be useful, such as if you're going to be gone on vacation for a week or two, as long as you understand the effect they have upon your CYA level.
 
A little "good news", my water seems pretty cheap should I need to drain some of the pool. I get charged a $13 monthly service charge plus $6.92 per 1000 gallons. If I drained the whole thing it'd cost me around $67 in water to refill it if I'm reading this rate chart correctly.
 
How much liquid chlorine and muriatic acid should I have on hand? I'm going to run to Menards and get chlorine, might as well get MA also since they have it there. I was thinking of grabbing 10 gallons of chlorine and a couple gallons of MA. That enough to start with?
 
Seems a good start. You might get away with only one gallon of MA for now, though. Unless it's a hassle to get more, might be better off. You have to store it away from metal and other chemicals, so personally I don't like having a lot of it on hand.
 
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It's generally safe to swim anytime the following conditions are met:

- FC is at or below 40% of CYA & at or above Minimum for your cya FC/CYA Levels
- pH is between 7 and 8
- You can see the bottom of the pool at the deepest point.
Remember- clear water doesn’t always equal sanitary water.
 
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Well i dumped a gallon of chlorine in per pool math. I forgot to do the diluted cya test prior to that though. Do i need to wait any certain amount of time before i do that test?
 
Ok so 100-120. You could either choose to use liquid chlorine and maintain it up really high to go with the CYA or exchange out some water, maybe half the pool to get down to 50-60 CYA.

I’d recommend pushing FC up to where it should be and doing an Overnight Chlorine Loss Test to ensure your water is clear. If that fails it might make more sense to exchange water in preparation for the SLAM Process. If it passes you can decide between maintaining high FC or exchanging.
 
I haven't done the overnight chlorine loss test, but I did test my FC again, and I'm at 16 now after adding that gallon of 12.5% chlorine. We got a pretty wicked storm last night and I just got done cleaning up. The robot's in the pool doing its job now on the bottom, but my water level came up pretty high. At what point should I drain water (I seemingly need to do that anyway so maybe take advantage of some free water?)
 

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