Free Chlorine Zero / TDS 3000 / water tastes salty --- help

Aug 16, 2012
5
We have had our fiberglass, 10,000 gal pool almost 5 years. It is CRYSTAL clear. I mean SPARKLING, but I am struggling with a few of things. Break down of my last test that I did with my test strips:
CH - 250
CC - 1
FC - .5 < 0
pH - 7.6
TA - 240
CYA - 150
TDS (Based on in store testing Tuesday (8/14) - 3000
My CYA has been high since install in 2007. They forgot they already put it in and put it in a second time. I've never added any since.

We have solar panels that heat the pool and it maintains about 92 degrees F. There was this odd debris in the pool that was either seeds or eggs (VERY small) that no one could identify. It would settle on the steps, bottom and sides but easily brushed right off with barely a touch of your hand. I would vaccum it up with the normal manual hose vac and they would return covering the pool in a couple days. I vaccumed up with a robotic vac and the smell was very fishy smelling. I pulled a full teaspoon of this out, hosed out the rest, and took it to the pool store. Still couldn't be identified. Again, crystal clear water. So I had the sand in the filter changed out on 8/7 and they said it didn't look odd at all, but the little brown specks seem to be going away now. When I backwash the filter the water is really white before it runs clear and leaves a white residue on the concrete. This is even since the sand was changed out. I have to assume this is caused by the high TDS??? Water tastes very salty. We have a lot of landscaping around the pool, but no leaf dropping trees. Living in NC we do not close the pool in the winter and just leave it running. The filter is run 24/7/365. There is no run off that goes into the pool. We live close to a farmers field, but probably more than 2 or 3 football fields away. Guy at Leslie's said the level of salt is almost like someone intentially put salt in your pool. I have no reason to believe anyone would do that.

Next problem, I cannot get my FC up. I was told that the shock I was using that had SODIUM DICHLORO-S-TRIAZINETRIONE in it (Bioguard Smart Shock), in conjunction with my chlorine tabs is helping to drive up the CYA and could be blocking the FC. It was suggested to stop using the tabs and just shock the pool with Calcium Hypochlorite instead of sodium dichloride. Monday I used one bag of Leslie's shock (forget the name). Didn't raise the FC at all. Tuesday I put in 2 bags of Power Powder and it seemed to raise it a little, Wednesday I put in 2 more bags of Power Powder but it doesn't seem to have helped much more. I'm not using any chlorine pucks at this time. With that said, my chlorine level is the best it has been in a long time. I also struggled to keep chlorine and go through more than 7 3" pucks a week. I assumed that is due to the temp of the pool and sun.

With these issues I'm at a loss. Never had any problems in the past other than keeping pH up. I am always add pH up to keep it above 7.0 and chlorine up. I'm also worry about the safety of using the pool. While there isn't a spot of algae, can there be other bacteria that I need to worry about? And I worry about damaging my equipment. The pool guy at Leslie said it is fine and actually joked that I could easily switch over to a salt water pool with the concentration of salt I have now. Thoughts???
 
Re: Free Chlorine Zero / TDS 3000 / water tastes salty --- h

:wave: Welcome :wave:

Confession, as soon as I read test strips, I skipped right over the numbers ... they are just not reliable enough to be trusted (neither are the numbers from pool stores actually). Looking back at your strip numbers and reading about all the pucks and powders you have been using, I am not surprised that you CYA may be that high or higher. What I am amazed by is that your water is clear. I have to think with the high CYA and low FC the pool is a algae time bomb ready to blow.

Given the numbers, my recommendation would be:
Order a good test kit. And then likely replace 75% of the water to lower the CYA into a reasonable range. Followed by ONLY using liquid chlorine instead of the solid forms that keep adding CYA (or calcium if you use cal-hypo).

I realize that likely sounds crazy to you given that the water is so clear ... but that is what the numbers you provided suggest. Now, if the numbers are WAY off (not an unreasonable assumption), then maybe your CYA is not quite that bad ... but no way to know until you get a good test kit.

It is not that uncommon for people to add salt to their pools to "soften" the water feel even without a SWG ... I have done it myself.

The dichlor and trichlor are very acidic and thus tend to lower pH ... although they tends to also lower the TA ... which in your numbers is high (so that again leads me to not believe the strips)

The pool guy might be saying it is fine, because there is a very good chance you will be in there shortly when you pool is green due to the lack of FC and high CYA valves and going to spend a lot of money.

BTW, if your CYA is correct at 150ppm, you should be maintaining your FC above 11ppm to ensure no algae starts ... which also leads to a problem that the pH test is inaccurate when the FC > 10ppm.

These are the facts based on the information provided.

I suggest you read through Pool School a few times to help understand the pool's chemistry and where I am coming from.

Ask questions as they come up of course.
 
Re: Free Chlorine Zero / TDS 3000 / water tastes salty --- h

Thank you very much for the information. Any thought as to why the TDS is so high and the water would taste salty? I've never added salt to the pool and the pool is only a few years old.

I've been reading information on this site for a few weeks now and plan to pick up the TF100 kit ASAP. I couldn't find my readings from the pool store from the other day, but they weren't "that" far off from my strips. I believe their TA results were lower than my TA reading, but the rest was pretty close from what I remember. The TDS I can't forget. Anyway, once I get the kit, I'll post new results.

Again, thank you!
 
Re: Free Chlorine Zero / TDS 3000 / water tastes salty --- h

We generally do not pay any attention to the TDS ... it is more important to know the levels that make up the TDS ... like CYA, CH, salt, etc.

I would not worry about. All forms of chlorine add some salt to the water ... and maybe the previous owner intentionally added salt. It will not harm anything.
 
Re: Free Chlorine Zero / TDS 3000 / water tastes salty --- h

My impression is that this pool was installed for the original poster and that they have not intentionally added salt ever. The Leslie's comment sounded like a "drive by salting" (homage to a Run By Fruiting).

People vary in their ability to taste salt so it's hard to know how much is in there. Salt testing strips would help understand that aspect.

Oh and another homage... Drain baby Drain... . Get the test kit - it is one of the only choices you have to keep things right without just tossing stuff in and guessing.

Where in NC are you located?
 
Re: Free Chlorine Zero / TDS 3000 / water tastes salty --- h

@ UnderWaterVanya
I'm in Kernersville, NC. Between Greensboro and Winston-Salem. And you are correct, I'm the original owner of the pool and never added salt or anything other than regular pool chemicals.

I just ordered my FAS-DPD Service test kit from Leslie Pool Supply. Can't wait to get it. I like being self sufficient!!! Will post more when I know more.
 
Re: Free Chlorine Zero / TDS 3000 / water tastes salty --- h

Confession, as soon as I read test strips, I skipped right over the numbers
I admit to the same thing. I skipped everything. Once your new kit gets in, you will be able to post numbers that will help us all help you get your issues resolved. :lol:
 
Re: Free Chlorine Zero / TDS 3000 / water tastes salty --- h

imangela said:
I'm the original owner of the pool and never added salt or anything other than regular pool chemicals.

I just ordered my FAS-DPD Service test kit from Leslie Pool Supply. Can't wait to get it. I like being self sufficient!!! Will post more when I know more.


Welcome to TFP :wave:

Depending on how much chlorine you have been dumping in the pool, that could be your source of salt. Most chlorine sources add salt to your water over time. Odd that you could actually taste it after only 5 yrs, but possible. Make sure to order salt test strips with the tf100.

Good luck
 
Re: Free Chlorine Zero / TDS 3000 / water tastes salty --- h

Good news is I got the TDS down and the CYA is slowly coming down. Drain baby drain... seems to be helping. Three feet down so far. Thinking I have 2 more to go. I don't even want to think about my water bill. Still waiting on the test kit to know for certain where I'm at.
 

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Re: Free Chlorine Zero / TDS 3000 / water tastes salty --- h

PAGirl said:
Have you thought of putting some of the unidentified substance in a bucket to see if anything grows?


I did think about it, but didn't actually try it. I'm collecting it now to take it to our Ag Extension office and have them identify it. Good and bad thing is, there's not much in there to collect since replacing the sand. That could be just a coinidence though.
 
Re: Free Chlorine Zero / TDS 3000 / water tastes salty --- h

Can someone tell me what is in "pH Up" and whether that affects salt or TDS as well as TA? (never used it so I have no comparison)
 
Re: Free Chlorine Zero / TDS 3000 / water tastes salty --- h

anonapersona said:
Can someone tell me what is in "pH Up" and whether that affects salt or TDS as well as TA? (never used it so I have no comparison)

It is sodium carbonate ... from Pool School:
Soda ash is available as ARM & HAMMER® Super Washing Soda Detergent Booster. Do not confuse this with ARM & HAMMER® laundry detergent! It is sold in the laundry detergent section of most larger grocery stores and some big box stores. It is also sold by pool stores under various names, including pH Increaser, pH Up, Balance Pak 200, etc. Soda ash is best added by pre-dissolving it in a bucket of water and then pouring that slowly in front of a return.

You can use pool calculator to see how much it affects TA (it does raise it some). I do not think it adds salt.
 
Re: Free Chlorine Zero / TDS 3000 / water tastes salty --- h

jblizzle said:
anonapersona said:
Can someone tell me what is in "pH Up" and whether that affects salt or TDS as well as TA? (never used it so I have no comparison)

It is sodium carbonate ...

You can use pool calculator to see how much it affects TA (it does raise it some). I do not think it adds salt.

Confirmed - Poolcalculator.com shows TA and pH are the only impacted values.
 
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