Can never get FC level maintained

Jul 25, 2011
28
For about a year now (seemed to start last August) either something crazy is going on or my SWG is not working. I have had my cell replaced, sensors replacement, and board part of the unit replaced. I am ready to switch over to straight chlorine. I have been dumping chlorine in by hand every night trying to maintain the chlorine level. Generally when I dump in the recommended amount of shock by the next morning it is all gone. If I dump in double the amount it stays in about a day. Before I started getting everything replaced on the generator I had the water tested several times and the water was perfect. And for the most part the water is always very clear, that is, as long as I don't forget to dump in more shock for more than a day or two. I have spent so much time and money on this, that I am ready to have someone come fill it in so I can get my yard back.

My water levels are a little off now, but were perfect. The last thing replaced was the board for the SWG. After replacing the sensors it said my salt water level was high. Which I told the rep was impossible seeing how last year the levels were perfect and I have not added salt in two years. So he convinced me to drain the pool down 4 inches and add water anyway. After draining water, it would flick back and forth from high to good. So he then replaced the board. But now it says with new board that the salt level is fine (3300) my ph is little low 7.2 TA little high 130 and CYA was a little low about 50 (I have since added 4 lbs of HTH CYA). My phosphate level is a little high about 200.

Sorry for rambling but after replacing everything, (the field guy even put the cell in a bucket and said it foamed meaning it was working), I still can not get the FC level maintained. It will literally goto to zero if I don't add myself. I have the SWG sensors turned off and the percentage set to 100%. Also I have an automatic cover, which rarely comes off during the day. So I literally should be using very little chlorine. In fact last year I had a problem with the chlorine level always running high.
 
Phosphates don't mean anything. Ignore that number, and ignore the pool store.

TA at 130 isn't too bad, I wouldn't concern myself with that. It wouldn't be too hard to get it lower if you want to do so though.

When FC won't hold, I check the CC level, and also I'll do an overnight chlorine loss test. Especially with the cover, it sounds like you need to shock your pool. Please understand shocking is a process, not a product. Here's the link to how to properly go through the shock process:
pool-school/shocking_your_pool

To do this, you are going to need a test kit with a FAS/DPD chlorine test in it. I suggest the TF-100 from http://tftestkits.net
You'll need to measure and hold free chlorine levels higher than a normal test kit can handle.
 
I have been shocking my pool about every night since May.

My water is also crystal clear. And has been all Summer except for about 2-3 days when I did not shock it for a day or two.

I definitely loose more than 1 ppm. Some days I will shock it well above 5 ppm and next morning less than 1 ppm
 
Welcome to TFP :wave:

Chlorinating to 5ppm is not shocking. It's just chlorinating and if you ahve had low CYA levels, the FC is burning off every day.

Your best bet will be to get at proper test kit, such as the TF100 from TFtestkits.net or the Taylo K2006.

The spens some time reading through Pool School. Link in my sig and upper right of this page :goodjob:
 
I leave my cover on during the day. So it should not be burning off. Also my CYA only measured low the last couple weeks after I drained water out to "supposedly" get the salt level down.

I said 5 ppm, meaning at least 5 ppm. The sticks I use only measure that high. It appears much higher than that. I would assume close to 10 ppm, but not sure.


I dump in 3-4 pounds of this about every night

http://www.intheswim.com/Pool-Chemicals ... ck-N-Swim/

Should I dump in 5, 6, 7, 8 lbs? My pool is 18 x 40 feet rectangle. Deep end 8.5 ft and shallow 3 ft. The contractor said about 26,000 gallons. Keep in mind the first year I had the pool I never shocked it once and almost always had high FC level. A couple times last year I had to dump in stuff to lower the chlorine because with the cover and the SWG using an auto sensing system (which never seemed to work right) the chlorine level would spike really high. That's why this year I was just going to run the SWG by % and just adjust it accordingly. But even at 100% and all new parts I can not get even low FC levels. It seems to me the only chlorine in the pool is what I have been adding every night.
 
Welcome to TFP :wave:

To take control of your pool, you need a good test kit. TF100 is the fav around here and the best bang for the buck. Contains Taylor reagents and they have excellent service. This is the best investment we made in our pool. Link in my sig. How do you test salt levels? Make sure you have that covered before you consider placing an order because http://www.tftestkits.net sells the salt tests separately.

We need test results, so if you could take a water sample to a pool store and post the results back here we can get started. As said, ignore phosphates. Don't buy anything at the pool store except liquid chlorine if they have a good price. :wink:

It 'sounds' to me that you have organics in your pool that are eating your chlorine and are overwhelming your SWG.

Stop using granular shock and only use bleach/liquid chlorine. The shock 'n swim you are/were using contains calcium. You can use plain unscented 6% bleach. Use Clorox,walmart brand, etc - just stay away from dollar store bleach regardless of brand. You can use liquid chlorine (same as bleach except about twice as strong %) found at the pool stores. Bleach/liquid chlorine (same thing, only diff strengths) do not add unwanted side effects.

So, post a full set of test results containing:
FC
CC
TA
CH
CYA
Salt

Is your water still clear? If not, describe how your water looks.

Add your pool/equipment specs in your sig. Go to User Control Panel (top left under TFP logo), select Profile, then Edit Sig. This will help us help you.

We'll get you thru this and soon you will also have a don't-want-to-fill-it-in-lovin-my 'trouble free pool' :-D
 
My water is perfectly clear.

I am going to take a sample to the pool store in a couple hours and will post the results.

If my SWG is working why is my ph level not rising? Last Summer when everything was working well. I had to lower the PH every two weeks or so because of the SWG would raise it when making the chlorine.

I went to Walmart looking for bleach. They had chlorox splashless regular, chlorox regular, chlorox HE regular, chlorox scented. They also had Great Value brand regular which was cheapor. Does it matter?
 
RobbieH said:
Interesting, I've never seen bleach specifically for HE machines.

Most folks that buy at WalMart use Great Value brand. Don't use anything scented.
And don't use splashless. Use Clorox regular or Great Value is good, too.

Use 6% plain bleach with no 'special effects'!
 
OK, I'm going to admit to just skimming this post, but I am time-limited right now. But the key, to me, is that you stated that you are losing chlorine overnight. This means that you have something organic in your water which the chlorine is fighting and you are losing your chlorine to it.
There are only two reasons for chlorine loss - UV or organics. At night, there is no UV, so...
Read up on shocking your pool in Pool School - there is a big button at the top right of the site. You will need to raise your FC to the shock level for your CYA concentration, and hold it there until you lose less than 1ppm overnight. Once that is done, then your SWG should have no trouble keeping up.
 

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test results today

TA 150
PH 7.2
CYA 95
FC 2
TC 2.75
My SWG says salt is 3400

Couple things the fc and tc seems pretty subjective when looking at chart.

Yesterday different tester said my CYA was 45-50 so I put in 4 lbs of CYA yesterday morning. Seems his test must have been way off as that should of only raised a 26,000 gal pool 15-20 points. Now I will have to drain some water. If I added the 4 lbs yesterday morning is it okay to backwash tonight? Will my level still rise some yet? I dumped it into the skimmer.

Another thing my SWG is turned on 100% and running 15 hours per day. Yesterday morning it tested about 3.4 FC and I never had the cover off but about 30 minutes last night after sun was behind the house. So it got little or no sun.
 
Racestud said:
Couple things the fc and tc seems pretty subjective when looking at chart.

That's why the FAS-DPD test is so much better. You count the drops and multiply. No interpretation needed.

Racestud said:
Yesterday different tester said my CYA was 45-50 so I put in 4 lbs of CYA yesterday morning. Seems his test must have been way off as that should of only raised a 26,000 gal pool 15-20 points. Now I will have to drain some water. If I added the 4 lbs yesterday morning is it okay to backwash tonight? Will my level still rise some yet? I dumped it into the skimmer.

Never trust pool store results unless you've verified their accuracy yourself. They are wildly inconsistent and useless in most cases. Some of it may still be in the filter, and backwashing would get rid of it.
 
Did you test the CYA yesterday or someone at pool store?

If you tested, what did you use?

I don't understand what 'different tester' means. :?

Why are you going to backwash? Is the filter psi indicating a need for cleaning?
If filter is okay, I'd leave off the backwashing until it is required/needed which would be a psi rise of about 6 over the clean psi reading.

If your CYA is near 70 (using some of your #'s) the shock level is about 28.
There is no way to measure that without the FAS/DPD kit.

If the CYA is closer to the pool store test of 95, then we'd recommend you dump some water to get to about 80 or so before shocking.
To better help you, we'd like to confirm test #'s.

What is the CH test number?

What surface type is your pool? plaster, vinyl, FG?

Where are you located, city and state?

It will be helpful if you add the sig.
 
Different tester means different person at the store. He did not seem as diligent as the person today. He normally does not do the testing.

Did not test CH

Vinyl

NW OHIO

I want to backwash because i am going to sweep the pool tonight and I don't want to CYA to rise anymore. Plus my psi is probably 4 or 5 over clean reading.
 
well opened the pool cover for about 4 hours this afternoon and the tonight the FC level was about zero as measured on one of them sticks.

So how do I know that the SWG is working? It is set to 100% and running all day, only shutting down at night for 9 hours. Wouldn't my PH be rising if the SWG was working?

I don't want to do this Super Shocking if my main problem is that the SWG is just not working...
 
Racestud said:
well opened the pool cover for about 4 hours this afternoon and the tonight the FC level was about zero as measured on one of them sticks.

So how do I know that the SWG is working? It is set to 100% and running all day, only shutting down at night for 9 hours. Wouldn't my PH be rising if the SWG was working?

I don't want to do this Super Shocking if my main problem is that the SWG is just not working...

Opening the pool cover will allow the sun to help burn of CC.

We could answer your test questions better if we had accurate test results.

Regardless of the reason for needing to shock your pool (or as you refer to as "Super Shocking") the need is still there.
The reason for the "need" will not remove the "need".

Try grabbing a sample for testing the FC at the return to help see if the SWG is producing.
 
I think you need to shock either way because you are putting enough cl in even if the SWG off. You must be losing it to something organic. If you are trying to get rid of excess cya then backwashing will vet rid any left in the filter. I waste into a drain so I don't know about wasting into the yard.
 

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