Pool trouble - Nitrates or other possible cause?

[bjc13]

I am getting ready to open my pool and I have been searching for a remedy for my pool problems. Last year,my first year being a pool owner, I had trouble getting a CHL reading. After getting my water tested, it was discovered that my nitrate levels were high. The pool store said there was nothing I could do and my pool would soon turn green. I treated it the rest of the summer by using Liquid Chl 12% once every 5 or so days and occasionally adjusting my PH. It was a pain to just guess how often to add chemicals because I was not getting any readings on my CHL test samples. My plan was to dump my water and just start over at the beginning of the new season.

So, I called the pool manufacturer to get info on how to drain my pool properly. One of the pool employees recommended pouring 1 gallon of liquid Chl 12% for every 1,000 gallons of pool water. My pool info is as follows: 16,000 gallons, gunite with DE filter, Frog system to Chlorinate. He recommended 25 gallons, just to be sure. Adding it by walking around the pool and dumping it in.

As soon as I heard this, I felt relieved to find a solution other than dumping my water. Then I spoke with a pool guy that opened my pool last year and he said I was crazy. Every time I hear a solution, someone else tells me not to do it. I'm very confused!!!! Any ideas?

 

[frustratedpoolmom]

I can pretty much assure you that your troubles have little to do with the nitrates and alot more to do with the use of the Pool Frog. Read about the Frog (and similar scams) here.

I'm willing to bet your pool was overstabilized (too high CYA) from using the trichlor Froggie bacpacs. That's why the liquid chlorine helped. Adding liquid chlorine is not crazy, it's the whole backbone behind proper pool chemistry.

As for guessing, I recommend you order a good test kit. Then you aren't guessing, and you aren't relying on pool stores who just want to sell you expensive chems like unneccessary Froggy accessories.

Once your pool is open, circulate the water for 24 hours and then have a water test done. Then post the results here and we can advise you better. In the meantime you can order a kit, we recommend two. Read about them here.

Then while you wait to open and for the kit to arrive, read everything in Pool School, then read it again. You'll be glad you did.

 

[spishex]

Every time I hear a solution, someone else tells me not to do it. I'm very confused!!!! Any ideas?

That's kind of how the pool industry works. A lot of mis- or under- education leads to a lot of confusion and conflicting opinions. Welcome to TFP, where profit doesn't drive the advice you hear.

What kind of test kit are you using now and what were your nitrate levels?

The advice you got wasn't crazy, but it was probably a bit excessive. At 16,000 gallons I'd probably add 2-3 gallons of shock per hour until your free chlorine held. Maybe it does need 20 gallons, but I wouldn't do it all at once.

 

[frustratedpoolmom]

Be sure to get the water tested before you begin to shock your pool.

If the CYA levels are too high, it's better to just start by draining some of the water out to lower the CYA, rather than try and shock with the higher range required. See the CYA chart for more info. The higher the CYA the higher your FC and shock levels.

 

[Guest]

The advice you got wasn't crazy, but it was probably a bit excessive. At 16,000 gallons I'd probably add 2-3 gallons of shock per hour until your free chlorine held. Maybe it does need 20 gallons, but I wouldn't do it all at once.

I concur! High chlorine levels will eventually burn off nitrates but it can take a LOT of chlorine to do so! Sometimes draining is actually cheaper. Unfortunately there is really no way to tell.

 

[bjc13]

I am going to try and open this weekend. Once I get it circulated I will post the water results. I currently have a Taylor Test Kit. So, if I am hearing everyone correctly, a total drain of my pool is not necessary. This problem can be corrected by finding my breakpoint chlorination. I can do this by adding Liquid chlorine in dosages of 2-3 gallons per hour until my free chl holds. What time of day should I do this? It might take several hours....

I appreciate all your responses and I feel like I've found a great place to get real answers.

Thanks

 

[frustratedpoolmom]

I am going to try and open this weekend. Once I get it circulated I will post the water results. I currently have a Taylor Test Kit. So, if I am hearing everyone correctly, a total drain of my pool is not necessary. This problem can be corrected by finding my breakpoint chlorination. I can do this by adding Liquid chlorine in dosages of 2-3 gallons per hour until my free chl holds. What time of day should I do this? It might take several hours....

I appreciate all your responses and I feel like I've found a great place to get real answers.

Thanks

You have found a great place. All sorts of experts on here from chemistry to builders to equipment.

Once we know your CYA level, then we can recommend whether draining/water replacement neccessary. There is no point in adding all that chlorine if your CYA is too high, you'll just find yourself having problems again until the CYA is lower. So wait until you have that test result.

Which Taylor kit, 2005 or 2006? Does your Taylor kit have the FAS-DPD test, like this one?

 

[duraleigh]

bjc13,

Welcome to the forum. Do not do anything to your pool until you get some test results. You may well have 0 CYA instead of an overdose.

Either way, the advice we can give you (without guessing wildly) is totally dependent upon valid test results for FC, TC, pH, TA and CYA Abbreviations are in "Pool School" if you don't know them already.

 

[bjc13]

I opened my pool today around 12pm. The results are from a test I ran at 6:30pm. Here are the results you had asked for:
FC .5
CC 1.5
TC 2.0
pH 8.2
T/A 150
CH .5
CYA 50
Temp 64

Water is clear from the time I took the cover off. I added 2 gallons of liquid chlorine on Saturday when I took the cover off. I have been vacuuming with Polaris and I brushed the walls and floor.

16,000 gal, in ground, DE, gunite with Heater. I think my signature will repeat this, but I wanted to make sure it was posted.

 

[JasonLion]

Your numbers are not bad. But there are a couple of things you need to do.

First, get the PH down to around 7.5.

Then shock the pool. See how to shock your pool at Pool School. Your CYA is 50, so shock level is going to be 16.

 

[bjc13]

I tested again after adjusting pH. Here are the results:
FC .5
TC 1.0
CC 1.5
TA 120
pH 7.4
CH 380
CYA 50
Temp 66

I am ready to shock, but I'm not sure if I understand exactly how to do this. I understand that I am adding liquid chl (12%), but how much? What does 16 refer to on the shock level? How soon after shocking should I measure for results? The POOL SCHOOL on shocking says to repeat if it does not hold at a certain level? What is that level that I am trying to reach?

 

[JasonLion]

Your shock level, given your CYA level is 16. That means you are trying to get a FC level of 16.

You enter your pool size, 16,000 gallons, current FC level, 0.5, and target FC level, 16, and bleach strength, 12%,, and my Pool Calculator will tell you to add about 2 gallons of 12% liquid chlorine. Note: liquid chlorine and bleach are the same thing, just sold at different strengths.

So you add the 2 gallons of chlorine by pouring slowly in front of a return. Then wait one hour (or more) and then test the FC level and repeat the process except using your new FC measurement in the Now column of my Pool Calculator. You want to do this as often as practical but not more than once per hour or less than twice a day.

Continue this process until the algae is gone, pool is clear, and the CC level is 0.5 or lower.

 

[mdhwoods]

I tested again after adjusting pH. Here are the results:
FC .5
TC 1.0
CC 1.5
TA 120
pH 7.4
CH 380
CYA 50
Temp 66

I am ready to shock, but I'm not sure if I understand exactly how to do this. I understand that I am adding liquid chl (12%), but how much? What does 16 refer to on the shock level? How soon after shocking should I measure for results? The POOL SCHOOL on shocking says to repeat if it does not hold at a certain level? What is that level that I am trying to reach?

Based on the pool calculator you will need 2 gallons 1 quart 1 cup of 12% chlorine to go from a fc of .5 to your shock level of 16.

16 refers to your target fc level you are shooting for. You want to maintain that level until you cc is .5 or less from evening to morning tests.

 

[bjc13]

Back again....I shocked several hours ago and just tested the water. I used the recommended amount and my results are quite a bit short.

FC 7
CC .5
TC 7.5
pH 7.5
TA 110
CH 420
CYA 45
temp 70

So, if I understand this correctly, I need to plug in 7 in FC and 16 in goal in the pool calculator and it will give me my amount of CHL to add. I should continue this until I reach my 16 FC? or should I do it until I reach 0 CC? Should I be concerned with my CH?

I really appreciate your guidance, as a new pool owner your site is a life saver!!!!

 

[JasonLion]

So, if I understand this correctly, I need to plug in 7 in FC and 16 in goal in the pool calculator and it will give me my amount of CHL to add.

Yes, exactly!

You continue the process until:

1) CC is 0.5 or lower and,
2) Either
a) the water is clear or
b) an overnight FC test shows no loss of FC overnight

 

[bjc13]

I tested this morning and FC was 13.5 (27 drops) and my CC was 0 or clear. I think that was a success! My kids are dying to swim, how long before it is ok to swim after shocking?

 

[frustratedpoolmom]

I tested this morning and FC was 13.5 (27 drops) and my CC was 0 or clear. I think that was a success! My kids are dying to swim, how long before it is ok to swim after shocking?

So your FC was 14.5-13.5 last night before you went to bed?

You can swim anytime the FC level is below your shock level.