SWG - zero FC

[wal81]

Hi TFP! I am having trouble retaining chlorine in my salt water pool.

I bought the house a week ago, and tested the water for the first time to find 0 FC. I spoke with the previous owner and at his advice added bleach to raise FC to shock level of 20 (CYA is 50). The next day, it looked better but cloudy in the deep end, and FC was about 10. Three days later (today) FC is back to 0. The water looks pretty clear but there a brownish yellow sediment on the sides and floor of the pool. The polaris vac cleans it up (or maybe just stirs it around) and it brushes off easily. I have no idea if this is pollen/dirt or algae. I went ahead and added more bleach today to bring FC up to 20 again.

I've read on this site and everywhere I can...I need to determine why FC keeps falling to 0. These are my theories:

1. Is there algae in the pool that keeps returning despite the shock level of FC? Wouldn't the SWG maintain at least some FC after the shock kills the algae? Could this be the dreaded mustard algae I've heard about? I know you recommend shocking and holding the level in your SLAM guidance (but you'll have to refer to my biggest problem at the end of this post...)

2. Is the SWG failing? The right lights are on, and it isn't giving me any alerts. However, I tried testing FC using water right out of the return, and it read 0 FC there too. Not sure if this is an accurate measure of SWG performance or not. Do I need to turn up the output percentage? I've had it about 40% with the pump running 12 hrs/day. Although I'm trying to leave the pump on 24 hrs at a time while adding all the bleach.

3. Could phosphates be to blame? I've read that high level of phosphates can cause a SWG to perform poorly. I've also read here that most of you consider phosphates not to be an issue. I had a pool store test the water just for comparison (don't stop reading), and their phosphate test showed 1200 ppb. I added 12 oz of seaklear phosphate remover today.

4. Could this be a result of CYA being too low? I know 50 is a bit low for SWG pools. The pool store test actually showed CYA of 10, but the members of TFP have said not to rely on that. If it really is 50, is that low enough to cause this big of a problem? The reading of 50 came from the TF-100 I got from the pool's previous owner.

Ok here is my biggest problem. I do not live at the house yet, and I'm currently an hour away. It isn't practical or possible for me to go check the pool every single day while I'm trying to fix this. Should I just put it on hold and start a massive attack in a month when we move in? Or is there a way to handle this with a once/twice a week visit? I'm going crazy over this! Ready to get a big excavator and smash up the whole thing! :taped:

 

[pooldv]

It is most likely algae consuming all the FC. Putting in bleach one time does not kill all the algae. Crank up the SWG to 100% and see what happens. All of the time the pool spends with FC under 4 or 5 then algae is growing more. I would leave CYA where it is right now to make it easier to SLAM when you move. The less you let algae grow now the less you have to kill later. Phosphates are not the problem. The only thing that stops algae from growing is chlorine.

TFPC for Beginners
ABC's of Pool Water Chemistry
SLAMing Your Pool

 

[jblizzle]

1. You can not just "shock" the pool once and expect all the algae to be gone. You have to maintain the FC at that shock level and follow the ShockLevelAndMAINTAIN Process.

2. Do you know how old the system is? It is possible that it is dying, but more likely there is just something in the water consuming the FC. A SWG will not over come that as it adds the FC too slowly. That is why during the SLAM, we generally recommend turning the SWG off.

3. Ignore phophates ... just a way to make your wallet lighter and the pool store's fatter.

4. Again, possible, but at 50ppm, if there was nothing in the water and the SWG was working, you should maintain FC levels. As stated in the previous post. Leave this alone until after you have completed the SLAM.

X. Oops, just saw the end. Likely you will have to just let it go until you move in. The SLAM process requires at least 2 application a day ... so 1/2 a week is not going to cut it.

What test kit are you using?

 

[Casey]

There is no sense in chasing your tail on a pool you can't be at until,you're there every day.

Educate yourself with the articles in Pool School so when you are ready, you'll have the knowledge to get the job done. If you have not ordered a test kit, now is the time.

 

[Isaac-1]

What they said, now one other thing, if you go to a pool store they will likely tell you to just give it one massive dose of chlorine to kill off all the algae bringing your FC up to some uncontrolled insane level. We call this nuking a pool, and the downside to this approach is that it will likely bleach out the pool liner, and considerably shorten its life, as well as damage other rubber seals and parts in your plumbing system. Things the pool store does not care about, after all where are you going buy all those new seals, pumps, liners, etc?

Ike

 

[wal81]

Thanks for the advice! A couple of follow up questions.

1. If I wait to deal with this later when I actually move into the house, will I be looking at a huge algae swamp by that time? Is there anything I can do in the meantime to help? Will adding bleach periodically do anything, or would that just be a waste of time and money? Is it ok to run the pump 12 hrs a day during this time, and should I leave SWG at 40-50? Pooldv recommended turning it up to 100% - how long is it ok to have it that high?

2. Can I leave my polaris pump in the pool during this - will it help deal with algae?

3. Is mustard algae a bigger problem than any other type? I have no idea what's growing in there. I'll attach a photo if I can.

What they said, now one other thing, if you go to a pool store they will likely tell you to just give it one massive dose of chlorine to kill off all the algae bringing your FC up to some uncontrolled insane level.

Ike

4. I appreciate Isaac's warning of pool store advice - what is the massive level they might try to recommend, just so I am armed with knowledge? When I went to the pool store to get my water tested (to compare with my TF-100) they were SO ALARMED when I told them I raised FC to 20 with bleach. They said that was insanely high, so I have no idea what their approach would be here.

Thanks everyone!

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View attachment 35967

 

[Azgirl71]

Just ignore the pool store and follow the advice you get on here.

 

[jblizzle]

1. Well the pool will get worse, but it may not be a swamp. If you can not consistently maintain shock FC level, then the algae will continue to grow, so you will kind of be throwing money away. If you want to feel like you are doing something, you could certainly raise the FC to shock level as often as you visit. It should slow the growth down, but will not likely eliminate the algae. Turning up the SWG might help maintain the FC level for longer. You can do that as much as you like, but it will consume more of the life of the cell. Think of the SWG as able to generate X amount of chlorine in its life, so running at 100% will just use up twice the life that running at 50% would.

2. You can if you want, but it will do nothing to combat the algae

3. I highly doubt you have mustard algae.

4. They are clueless. They would likely recommend a bunch of dichlor packets that would raise the FC even higher. Just ignore them.

 

[Griswald]

Looks like pine tree pollen to me, typical in the south. Lots of vacuuming and back-flushing in your future. (took me 3 times to get it all out yesterday).

Like others have stated, slamming is a time consuming process...if you really need to slam once you remove the pollen. I'd wait, after removing my pollen, it took only one gallon of bleach to get me to roughly 4.0 chlorine and then I turned on the SWG. I will test again today and go from there.

P.S. Get the TFT 100 test kit, best money you will spend on your pool.

 

[DaninFLA]

I had the same issue with my SWCG. even running for 12 hours at 100% I couldn't get the FC above 1 ppm. I cleaned the cell with diluted muriatic acid to clean up any calcium building (btw, I would recommend you do this as well, even though its not the issue). the SWCG is fine for keeping up with the FC levels once the pool is setup from a SLAM. It just cant create enough chlorine to play catch up. if I were you, whenever you are there I would dump a bunch of bleach to get past your shock level. it wont fix the issue, but I bet it will be in better shape when you finally get into the house and can do a proper SLAM.

 

[jblizzle]

I if I were you, whenever you are there I would dump a bunch of bleach to get past your shock level.

This is not recommended by TFP ... now if Dan is willing to accept responsibility for any damage that occurs to your liner by raising the FC very high, that is between the 2 of you.

 

[DaninFLA]

This is not recommended by TFP ... now if Dan is willing to accept responsibility for any damage that occurs to your liner by raising the FC very high, that is between the 2 of you.

we raise FC to shock level...that's what I said. I think everyone would agree when we do that, its "a bunch". how is that incorrect?

 

[wal81]

Pine pollen is likely - there are lots of pine trees in the vacant lot next door. BUT would pollen cause this problem of 0 FC and the SWG not being able to keep up?

Can you always SEE algae to know if there is an algae bloom that could be eating up all the FC?

P.S. Get the TFT 100 test kit, best money you will spend on your pool.

I have the TF-100 kit that the previous owner left me. It might be a couple years old. Is it still reliable? I am planning to get a refill anyway.

 

[wal81]

Also...is there a way to test to see if the SWG is generating chlorine at all?

 

[Azgirl71]

Also...is there a way to test to see if the SWG is generating chlorine at all?

With the SWG on look to see if there are little bubbles coming from the return is the easiest way. If there are not then your cell may have gone out.

 

[jblizzle]

we raise FC to shock level...that's what I said. I think everyone would agree when we do that, its "a bunch". how is that incorrect?

Your post was not clear and seemed to endorse raising the FC above shock level. It was easy to misinterpret that as recommending just nuking the pool with a "bunch of bleach" as a pool store would suggest ... and ignoring the shock level recommendation.

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Algae is not always visible.

You can try to gather some water right out of the SWG or out of the return jet as see if the FC level is higher. Realize that the SWG is not always generating and make sure it supposedly is when you try to test.

 

[DaninFLA]

Your post was not clear and seemed to endorse raising the FC above shock level. It was easy to misinterpret that as recommending just nuking the pool with a "bunch of bleach" as a pool store would suggest ... and ignoring the shock level recommendation.

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Algae is not always visible.

You can try to gather some water right out of the SWG or out of the return jet as see if the FC level is higher. Realize that the SWG is not always generating and make sure it supposedly is when you try to test.

well sorry for not being specific. bunch...as in the amount need to get to shock level

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Also...is there a way to test to see if the SWG is generating chlorine at all?

you should be able to look at the diagnostics when you cycle thru the screen on your controller. post those on here. you can also remove the cell and take it to a pool store, many of them can hook it up and run diagnostics.

 

[Griswald]

Pine pollen is likely - there are lots of pine trees in the vacant lot next door. BUT would pollen cause this problem of 0 FC and the SWG not being able to keep up?

Can you always SEE algae to know if there is an algae bloom that could be eating up all the FC?



I have the TF-100 kit that the previous owner left me. It might be a couple years old. Is it still reliable? I am planning to get a refill anyway.

The pollen cannot keep the SWG from creating chlorine, but the pollen could be using up all of the chlorine that the SWG can create simply by being organic. Remember, a SWG can make chlorine in SMALL quantities, enough to maintain your levels. Seems that they are really poor at generating a LOT of chlorine, like what you need at start up. And, NO, you cannot always see algae. It can hide anywhere until all of a sudden...green water.

The reagents in your kit might need replacing, they are relatively inexpensive to replace, probably a good idea.