Post-Algae: New Pool Owner needs Second Opinion

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B

Beach_Bum_at_Heart

0
Apr 8, 2017
23
Lawrenceville, GA
I just purchased a home with an approx 8300 gallon pool that has a salt water chlorinator. The pool went dark green on me after a couple heavy thunderstorms last week. I was able to get the pool cleared up with some heavy shocking and I just went back to the pool store for a water sample test. My readings were:

TC: 8.8
Free Chlorine: 8.8
pH: 7.9
Total Alkalinity: 4
Adj. Total Alkalinity: 0
Hardness: 198
CYA: 122

His advice was to add two more pounds of shock tonight. Tomorrow add 12lbs Alkalinity increaser in thirds (waiting 6 hrs between each). Then add 1/4 gal muriatic acid the following day.

I was interested in other people's opinion--especially because I wasn't expecting him to say add more shock after my levels are already high. I was also curious about the CYA. He said he doesn't want to touch it because it's good, but I think I want that just below 80.

Part of my request for another in opinion is I've read so many blogs and forum posts on this site that I have a good idea where my levels should be, I just need to know the right steps to get there, how long to wait before each step, etc.

Any suggestions would be greatly appreciated.

Thank you


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Welcome to TFP! Your one stop for testing your own water and keeping it sparkling. I hope, and think, your TA number is incorrect. I highly suggest you get your own quality test kit so you can ensure your test numbers are correct. We recommend either the TF100 or the Taylor K2006C.

The stock reply from all pool stores will be add shock. That is what they were told when they were trained. Once you get a quality test kit of your own, we will have a good set of numbers to be able to advise you on.

you will need to SLAM your pool to get it going in the correct direction. Please read through PoolSchool link at top to get a good understanding of what we suggest and, more importantly, WHY.

Once again, welcome!
 
Hey there BeachBum Welcome to TFP! :handwave:

As soon as I read your "test results" I knew they came from a pool store. Since you didn't mention "phosphates" I'm guessing it wasn't Leslies? LOL Leslies is always trying to scare folks in to buying a totally unnecessary phosphate killer that its sort of a joke around here.
We don't trust pool store test results at all. They are often done hurriedly and the equipment is out of calibration. They're not using anything special in fact to test.

We encourage EVERYONE to have their own test kit. There are two on the market we recommend: The TF-100 or the Taylor K-2006C. Both use Taylor reagents but the TF-100 is a better buy because it includes more reagents for the tests most commonly done.
You can obtain them from: Tftestkits.net or PoolSupplyWorld.com or Amazon. Tftestkits.net ships the fastest to GA.

If we are to believe your test results your CYA if far too high and requires a partial drain and refill. Each time you add a granular or puck chlorine/shock product you are also adding yet more CYA to your water and compounding the problem. We suggest using liquid chlorine (aka "bleach") instead. No unwanted extra ingredients to cause you problems in the pool.

Your TA is totally whack. I can't suggest anything there except a better test kit.

Here is some reading to help you understand our methods:

ABCs of Pool Water Chemistry

Pool School - How to Chlorinate Your Pool

[FC/CYA][/FC/CYA]

Pool School - Recommended Levels

Bring back any new questions, we're here to help!

Yippee :flower:
 
BBaH,

Welcome to TFP... A Great resource for 2nd opinions... :shark:

You, my friend, are being Pool $tored... the only why to stop spending your money is to stop going to the pool store!!!

Thunder storms did not turn your pool green... the fact that your CYA is so high and I suspect your FC was so low that it allowed algae to grow.

Check out this chart.... https://www.troublefreepool.com/content/128-chlorine-cya-chart-slam-shock

The chart shows the relationship between CYA and how high your FC needs to be to compensate for it. Notice that our charts don't even go near a CYA of 122. And, I highly suspect your CYA is even higher than that.

Your TA must be a typo, it can not be that low.

We can help you get this all cleaned up and keep you out of the pool store forever, but you have to do two things..

1. Read our "Pool School" using the link at the top of this page.

2. Get one of our recommended test kits. (I recommend the TF-100)..

So... I can see your mind working from here... "This site just wants me to buy one of their test kits, they are no better than the pool store"... :mad:

Well, we are all volunteers, so nothing is gained by us when you buy a test kit, but everything is gained by you.

Once you have a test kit, you can report your readings back to us. We can then point you in the right direction to get your pool back into shape.

We can't use pool store data because most of the time it is wrong. We can't use other tests kit because we have to compare apple to apples. We need to know that what you are using is the same as what we use, so that our advice is accurate and makes sense to both of us.

Thanks for posting, and I hope you stick around,

Jim R.
 
Thanks, everyone. I ordered a test kit based on everyone's recommendations. It should arrive Wednesday. I used a test strip this morning in the interim and it was close to the local pool store's readout. The pool was open when the prior owner was showing it and he had a lot of shock in the garage that he left for me. My suspicion is the CYA was raised during the showing of the house due to the fact the prior owner wanted it to look super clean for selling purposes and then even higher due to my shocking it for the algae. I do need to raise my Alkalinity based on the results of the test strip and my chlorine levels were off the chart based on the test strip, but I realize I probably shouldn't do anything until I lower my CYA, so I'm handling that now while I wait for the test kit. I'll post the results I get once it arrives.


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Welcome to TFP! Two more days until your test kit arrives!!

Believe it or not, your FC levels may be too low. But agreed, your CYA number by a "good" test kit is need to confirm that and your next steps. Proper FC levels are relative to CYA levels. Your comments about your FC being too high are based on not considering the buffering effects of CYA. If this is confusing, that's OK, just says a little more Pool School is in order for you. How is the reading of the Pool School links above going? We expect you to have some questions to confirm your newly gained knowledge!
 
Good catch and thank you for that reminder. I admit I was scratching my head last night when I read analogbytes's comment about adding liquid chlorine because I thought my FC level was well above the ideal range- especially since the FC and TC numbers were the same. So because my CYA is so high I need to assume my FC level should be higher as well. I did read that the higher the CYA the more frequently I'd have to add chlorine, but I (somewhat nervously) figured it would be safe to hold out until the kit comes. I'm trying to prevent adding anything additional until the kit arrives because I have a hunch I'll have to dilute the water through backwashing and refilling.

The Pool School links have been helpful. It's a lot of information to take in and it's a bit difficult to prioritize without a good test kit. Since I have a SWG I read that article, the article on slamming, and the CYA/FC chart, as well as the one's mentioned above.

I saw an article on how to test for FC using the FAS-DAD kit, is there an article on testing CYA and Alkalinity? I imagine the kits come with instructions but I was just curious. Anything else you all recommend reading until Wednesday?




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Sorry my response confused you. If your CYA is 100+, and it very well may be, you are good for FC of up to 39 ppm as that is the shock level. I am not saying you should bring it that high at the moment since we are unsure of your CYA, but keeping a very healthy dose of chlorine in there until your kit arrives will help the situation not get any worse.

Here is a link about testing. Pool School - Extended Test Kit Directions

- - - Updated - - -

Oh, and I got that value from Pool School - Chlorine / CYA Chart

- - - Updated - - -

One last update. Just to be clear, chlorine is the only thing you should be adding without numbers from a good test kit.
 
Here's one... and there are a few others on their channel. Note that when reading the CYA test, it's back to the sun and tube at waist height, tube in the shade.

TFTest Kits CYA Testing Video

There is definitely a learning curve on the knowledge and testing. Shorter on the testing than knowledge. But once the knowledge clicks, and it will, you will be golden.
 

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Analogbytes said:
Sorry my response confused you. If your CYA is 100+, and it very well may be, you are good for FC of up to 39 ppm as that is the shock level. I am not saying you should bring it that high at the moment since we are unsure of your CYA, but keeping a very healthy dose of chlorine in there until your kit arrives will help the situation not get any worse.

Here is a link about testing. Pool School - Extended Test Kit Directions

- - - Updated - - -

Oh, and I got that value from Pool School - Chlorine / CYA Chart

- - - Updated - - -

One last update. Just to be clear, chlorine is the only thing you should be adding without numbers from a good test kit.
Click to expand...

No need to apologize. My confusion had nothing to do with your post, I assure you :). Thanks for the additional insight.
 
OK... so the kit came in Wednesday and the first thing I did was test the stabilizer, which was high. So I partially drained and refilled, then tested again today. I had some issues testing which I'll explain in more detail next to the results listed below. I used a Taylor Technologies K-2006 test kit:

FC: 45 ppm, but the solution never turned clear. I recorded this result after it turned purple. This was the first time I actually saw it change and the highest I went from a drop perspective.

CC: Not tested due to note above.

pH: 7.5 - I tested this twice because the first test turned darker after 20-30 seconds, but this was my initial reading each time. Is that normal for it to look darker after 20-30 seconds or so?

TA: 1125 This never turned red. It turned from green, to blue, then finally yellow. I'm not sure if I should have kept going, but I eventually gave up when it stayed yellow and I was hitting this high of a number. So this wasn't the "just-turned-yellow number". Should I have just taken the yellow change as the reading? I imagine I should have kept going, but I was a little frustrated at this point.

CH: 190

CYA: 105/110 - this was just over the 100 line. Yesterday it was higher (probably 120/140)


We're expecting some more storms this weekend, which I'm optimistic will help with diluting some of this, but I'm also concerned it'll end up turning green again. Any thoughts on where to start, or feedback on the above issues I experienced would be immensely helpful and appreciated. Thanks in advance
 
FC, you may have extremely high FC. If so, you will need to add more DPD powder. Read this page paying attention to when it talks about high FC. Pool School - FAS-DPD Chlorine Test test using 10ml sample
If your FC is over 10, don't bother testing pH as in will not be correct.
Holy TA! Again, extremely high FC can cause issues with this test(need to add more R-0007), read this page Pool School - Total Alkalinity test using 10ml sample
With CYA over 100, you should perform a diluted test. See number 9 here. Pool School - CYA

All in all, make sure all sources of chlorine are removed and SWG is shut off.
 
Okay the tips for high FC definitely helped. I don't know how to power off my SWG, but I lowered it's output to 0%-- I assume that's an equivalent action. New readings are:

FC: 26ppm (this is the average of two tests)

CC: 0

pH: not tested

TA: ~200ppm

CYA: 120ppm

CH: 230ppm

I'm still tempted to do more draining and refilling, but with the storms expected Sunday - Tuesday, I wonder if it would be best to wait for those first and see how they impact the CYA and FC?

I'm also curious what impact diluting either through rain water or partial refills will have on TA. Should I start adjusting that down now regardless of the decision on CYA?

And finally, how long should I wait before I test CYA again if I try to partially refill?


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Glad we got you some good numbers! Ok, SWG at 0% is perfect. The 120 on CYA, does that mean you got 60 with the 50/50 dilution test? A partial drain and refill will be necessary to reduce CYA. Once you refill, mix the water good with the pump and retest, 30 minutes is plenty. If you have storms coming, you could drain a few inches to collect some free water.

Test your tap water for TA and CH so you will have an idea on how tap water will affect those 2 items.
 
Analogbytes said:
Glad we got you some good numbers! Ok, SWG at 0% is perfect. The 120 on CYA, does that mean you got 60 with the 50/50 dilution test? A partial drain and refill will be necessary to reduce CYA. Once you refill, mix the water good with the pump and retest, 30 minutes is plenty. If you have storms coming, you could drain a few inches to collect some free water.

Test your tap water for TA and CH so you will have an idea on how tap water will affect those 2 items.
Click to expand...

Yes I got 60 with the 50/50 dilution test for CYA.

So after the drain and refill, run the pump at least 30min before testing again and I should have a fairly accurate reading? How far down should I drain? I've been staying just above the bottom of the skimmer:

32ef12ea0de9c4bfff1dd108fbbc9b31.jpg


Is it safe to go below that? I'm afraid I'll get air in the skimmer line if I do. I'm using the backwash setting, so I don't know if the skimmer line is running on that setting. I feel like this is def a main suction point at the bottom of the pool:

fe7bdf81dcbdf55b19dce38c1b2387ca.jpg



Thanks for the quick reply and all the help. I'm working from home today so if I can tackle this now I'm all for it lol



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Easiest way is with a sump pump. You can pick one up for about $40 or rent one for about $20. What CYA are you planning to shoot for?

- - - Updated - - -

CYA of 70 or 80 is what you should be shooting for. Plug size of pool in poolmath, and the now and target for your CYA and it will tell you how much to drain/refill.
 
Alternatively if you have a main drain you can close off the skimmer and use the main drain only, and then turn your multiport valve to "waste" which bypasses the filter entirely. Where does your water go when you backwash and waste?

Yippee :flower:
 
It connects to a sewer drain that our neighbors had installed in their backyard. The filter shoots the water through the ground and feeds out there

The filter's labels are completely gone for the most part. Not sure which one is the waste setting

24d67cdcb96447131179a8e37b907567.jpg


I know backwash, rinse, and filter... not sure which one is waste, but I'll look it up online and see if I can find a similar label. Waste doesn't use the skimmer?


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