Issues with FAS-DPD test and Getting Pool Clear

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Lhnm1975

0
Aug 21, 2015
14
Dallas, TX
Newbie pool owner and having lots of trouble! Pool was swamp green when we moved in about 5 weeks ago. Husband went to Leslie's and was told to shock and use algaecide. Pool improved slightly, but was still green. CYA was 0. Pool store told him to deal with the green first and then deal with CYA. Went through shock and algaecide treatment a second time. Pool still wasn't clear. I ordered the Taylor K-2006 test kit and decided to get the CYA up with liquid stabilizer. Added enough to get it to 30 and started SLAM. It has been about a week and a half and probably 50 bottles of bleach and still don't think we've won the battle. Have yet to measure less than 1cc. Pool aqua color and looked clear Sunday. I ran out of R-0871 on Saturday so wasn't able to test again until today (Monday). In the meantime added about 6 jugs of bleach between Saturday afternoon and Monday morning. Monday afternoon I tested the water and had discrepancies with the FC and CC. I did the test several times in a row with different results each time.
1) FC=4, CC=6.5
2) FC=7.5, CC=3

After about two hours I got another water sample and got these results:
1) FC=4, CC=5.5
2) FC=7, CC=2.5
3) FC=3, CC=6.5

The odd thing is each time the TC was the same. What is going on with this test?! And what is going on with my pool that I just can't seem to get it clear?

Other test results are:
PH 7.4
TA 100
CH 210
CYA is less than 30 (black dot did not completely disappear)

We're adding about an inch of water every day. Not sure if it is evaporation out a leak. Will try bucket test tomorrow.

It's a fiberglass pool about 22,000 gallon. (Sorry, couldn't figure it how to add a signature and it's late!)

Thanks!
 
Wow...and inch a day waterloss sure sounds and feels like a leak to me.

In addition to the SLAM have you been brushing, vaccuuming and cleaning/backwashing your filter? I'm pretty new to this and the gurus will surely chime in, but I would think you would need to get the dead stuff out. I agree with the pool store. You want to attack the problem before raising your CYA anymore. You have to get CC down, and I think the only way you will get there is to kill everything that is in there. How many times a day are you checking the FC/CC levels? Given the numbers you are at, I would start checking every few hours if you can...at least at night if you work during the day and making sure your FC is above 12 at all times.

BTW, what is your OCLT showing you?

Again...been doing my own pool for only about 8 months...so hopefully someone smarter than me will chime in.
 
I am a bit concerned about your inconsistent FC/CC test results, if you would walk us through when and how you are doing the test perhaps we can spot where you are having problems. This may be as simple as not getting a good sample, always get a sample in a location with good circulation, at least 30 minutes, preferably an hour after the last chlorine addition from at least elbow deep water.
 
I would like to just mention, that if the pool was (or still is), swamp green, what is the possibility of lots of muck on the bottom?

It makes perfect sense that if the bottom is mucky, that you arent seeing any improvement.

SLAM Rule 1 on a swamp green pool is to get all of the muck, leaves, sticks and whatever else is there, off of the bottom and out of the pool.
Its not a maybe someday type of thing. It has got to go or you will be fighting a loosing battle no matter what you do.
 
D
Divin Dave said:
I would like to just mention, that if the pool was (or still is), swamp green, what is the possibility of lots of muck on the bottom?

It makes perfect sense that if the bottom is mucky, that you arent seeing any improvement.

SLAM Rule 1 on a swamp green pool is to get all of the muck, leaves, sticks and whatever else is there, off of the bottom and out of the pool.
Its not a maybe someday type of thing. It has got to go or you will be fighting a loosing battle no matter what you do.
Click to expand...

I could not agree more. This needs to be addressed and out of the way.
 
I agree, that has to be a ton of organics that use a lot of chlorine to die....you'll want to vacuum that stuff (to waste ideally I think) and then the SLAM should go faster. Dead algae should turn your water blue-white, if it's still green there's living stuff.
 
Thanks for your replies! Sorry I've been MIA since I first posted! Lots of other stuff going on and this pool driving me nuts. Anyway, I did some more looking around on this site and found a thread that sounds very similar to my issue with the FAS-DPD test. His results were also all over the place and it turns out he had high ammonia. So I'm planning to get an ammonia test kit tomorrow to see if this is my issue too.
 

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Re: ammonia -- if you immediately loose half your FC in such a test, that usually indicates you have it, and the answer is to just keep dosing and testing until FC holds...so just like an uber slam for all intents and purposes.

But if you've been slamming for a number of days and have been and holding your FC above slam level at all times -- which is requisite in a slam -- then it's far less likely an explanation of what's going on. While cya can convert to ammonia in rare "0 FC" stagnant conditions, it is also usually conquered in the first frequent additions of FC until you have a FC that will hold.

There are other things that will skew your readings, such as some components of treatments you might have applied from the pool store, eg MPS that gives a false cc reading, and in some cases, formulated ammonia products (eg Green to Clean) which act a bit differently due to their deliberate formulation:

Pool store told him to deal with the green first and then deal with CYA. Went through shock and algaecide treatment a second time
Click to expand...

So...to put this baby to bed:

1. List the names of products pool store had you add...it may help dx what's going on with your testing

2. Post a pic of your water

3. Confirm that during your 50 gal over the prior week and a half that you had actually been able to hold FC at slam level for your confirmed cya reading prior to the strange tests on Monday (btw, I used more than 50 gallons in 12 days recovering a swamp, so that of itself doesn't necessarily indicate anything abnormal except that you're fighting a heroic recovery ;))

4. Confirm that you've removed all debris you could from floor of pool.

That will help us rule out causes and get the slam monkey off your back quicker ;)

In case you didn't come across this in your reading about slamming, algae will outpace you any time your FC drops below effective kill rate.

So if your cya is truly 30, your slam level is 12, but in your shoes I might dose to 14 or 15 so that a few hours later it wouldn't be much below 12...that way the majority of the interlude have been above or at the effective kill rate.
 
Just a quick reply for the moment. I added enough bleach last night to get the fc up to 13. An hour later my fc was 3 and cc was 7. I added another 3 gallons to get it up to around 13. This morning before any sun was on the pool my fc was 1.5 and cc 1.5. When the pump is off the pool is clear. No debris on the bottom. Color right now is almost blue, but a bit of a gray haze. I haven't been able to get CC below 1.5 and usually it's higher.

- - - Updated - - -

Also wanted to add, every time I add bleach some foam forms in parts of the pool. And the pool starts to smell noxious right after the addition of the bleach.
 
I agree any debris on the bottom needs to be removed either by vacuuming, or using a leaf rake on the bottom of the pool.

The FC levels are dropping so quickly because there is debris or something in there causing it to be rapidly used up. With the CC levels reading so high at 5 and 6ppm at times that tells me there is a lot of debris/stuff in there combining with, and consuming the chlorine you are adding.

As far as the foam are you certain the bleach is not splash less?

With the smell it does make me suspect you have a lot of outgassing because of your high combined chlorine levels. If you continue to bump your FC level up, and maintain it at the Shock level of 12ppm, or slightly higher for your current CYA you should soon get ahead of the problem, and start seeing better holding in your FC as well as a decrease in your CC levels. But 1st please ensure the bottom of the pool is completely clear of any debris.

Also make sure you are brushing the walls, the area between the wall and the floor of the pool, the pool floor, lights, returns a couple times daily if possible, and remove any ladders/steps out of there if possible because that could be where the debris is hiding that is consuming all your chlorine.

You will get there, I promise. It may take a little while to do so, but you are not alone, we are all here to help you in any way we can. Have a wonderful day. :)

EDIT: The pH reading will Not be accurate with a FC of 10ppm, or higher. So, there's no need to test anything other than FC and CC until your SLAM process is completed.
 
Ugh! Can't keep enough bleach at the house. I dumped in 3 gallons about an hour and 20 min ago which should have raised FC to 13. Just tested and both fc and cc are 1.5!! That's 12 gallons used in about 12 hours!! I don't have time to get more bleach for a few hours. Is this going do be a case of two steps forward and step back? I'm using my phone for these posts and can't see how to post a picture. But the pool looks inviting, just the numbers don't.
 
Lhnm1975 said:
Ugh! Can't keep enough bleach at the house. I dumped in 3 gallons about an hour and 20 min ago which should have raised FC to 13. Just tested and both fc and cc are 1.5!! That's 12 gallons used in about 12 hours!! I don't have time to get more bleach for a few hours. Is this going do be a case of two steps forward and step back? I'm using my phone for these posts and can't see how to post a picture. But the pool looks inviting, just the numbers don't.
Click to expand...

Even though the pool looks clear, That can be deceiving. The numbers are telling us it is not yet adequately sanitized, and therefore can cause algae to grow, and can breed bacteria that can make you sick.

It's not so much "a case of two steps forward, and a step back," as much as it is getting ahead of the problem, and then ensuring the chlorine levels are maintained there to prevent algae growth, and unsanitary swimming conditions. We all just want to ensure the water you swim is in fact as inviting as it appears. It will take some time and some bleach to get it there, but once it does it will be so worth it. Have a wonderful day :).
 
You just need to keep at it until you burn off whatever is rapidly consuming your Chlorine (possibly ammonia that is a biproduct of the nasty stuff in your pool breaking down), once it is gone your FC level should rise like expected.
 
Lhnm1975 said:
Just a quick reply for the moment. I added enough bleach last night to get the fc up to 13. An hour later my fc was 3 and cc was 7. I added another 3 gallons to get it up to around 13. This morning before any sun was on the pool my fc was 1.5 and cc 1.5. When the pump is off the pool is clear. No debris on the bottom. Color right now is almost blue, but a bit of a gray haze. I haven't been able to get CC below 1.5 and usually it's higher.

- - - Updated - - -



Also wanted to add, every time I add bleach some foam forms in parts of the pool. And the pool starts to smell noxious right after the addition of the bleach.
Click to expand...

The pump should stay on, if possible. Have you back washed lately? You haven't mentioned what else, besides bleach, you might have added to the pool previously, up to a week or two ago. Bleach should not foam when added. The splash less kind might.
 

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