Direction Requested

[JGenova]

Hi all,
We just bought a home that has an in-ground pool, and have likely made a few mistakes. We want to switch to the TFP method, and have been reading everything like the ebook and ABC's, etc., but could certainly use some support. We use the pool calculator app also.

Some Background
The pool was opened on 5/4...we had a pool store do it because we did not know what we were doing....mistake #1. They were pretty terrible (put the wrong amount of DE in, threw a bunch of shock and left). They said bring in a water sample after 48 hours, which we did, but they told us we needed something like 10 gallons of liquid chlorine (12%) because our FC was low and CC was high.

There was quite a bit of organic material at the bottom of the pool and on the slants going from the walls to the floor. We vacuumed to waste and brushed everything.

At that point we decided to test ourselves using the K-2006 Test Kit. We ended up showing CYA below 30 (store's test said 5), PH 8, Alkalinity 55. In the mornings, our FC was low, around 1 or 2, with CC being higher (5 or 6). We decided to SLAM, but wanted to get our PH better first, so we added BioGuard Lo'n Slo which was basically just dry acid. This brought PH down to 7.5, and alkalinity to 45.

While waiting to SLAM, we added a gallon of 12% bleach to have some FC in there before we did the SLAM. Last night, we added 5 lbs of CYA via the sock method according to the pool calculator because we thought we needed to be at CYA of 30 before the SLAM. We added another 2 gallons of 12% bleach last night.

Test Results and Water Visual

Original results (5/6)
FC: .6
CC: 2.0
PH: 8
TA: 60
CH was in normal range, but I did not record it.

Today's results:
Our results this morning (9 am)
FC: 6.6
CC: 1

We tested again at 10:30:
FC: 2.8
CC: 4.8

We then added 1.8 gallons of 12% chlorine to get to FC of around 16 according to the pool calculator (16 was the target if the 5 lbs of CYA eventually bring us to 40 CYA) although FC has not reached that number at all.

12:00 pm:
FC: 2.5
CC: 5.5

2:30
FC: .8
CC: 3.4

The water looks somewhat clear in the morning but by later afternoon/evening is cloudy and a tinge of green when the pool light is on. It smells like chlorine after we add it, but by evening smells like a lake. Pump and filter have been going pretty much non-stop since opening.

Questions
1. Where do we go from here? We haven't been able to get to shock level.
2. Do we have an ammonia problem if the CYA was so low and the FC is being used up so quickly?
3. Do we need to superchlorinate (bring FC to 10x the CC) and then SLAM until we pass all 3 criteria?

Thank you.

 

[ajw22]

• Add 10 ppm of liquid chlorine to your pool
• Test your FC after 30 minutes
• Repeat until your FC holds > 3 ppm after 30 minutes
• Only then check your CYA
• Add 10 ppm of CYA at a time until you get to between 20 and 30 CYA
• Start the SLAM Process

 

[JGenova]

Thank you. A couple of follow up questions. To clarify, we have already added 5 lbs of CYA last night, dissolved through 4 socks in the pool. I didn't know that I was supposed dissolve 10 ppm at a time.

Since we added CYA already, does that change the amount of liquid chlorine I should be adding and expecting to hold after 30 mins?

Finally, I will be able to add every 30 minutes tomorrow, but Monday is back to work. I can test and add chlorine before work, but no one will be available for 8 hours. Should I add more chlorine based on that? How many days is it expected to take to hold > 3 ppm?

 

[ajw22]

Thank you. A couple of follow up questions. To clarify, we have already added 5 lbs of CYA last night, dissolved through 4 socks in the pool. I didn't know that I was supposed dissolve 10 ppm at a time.

The reason for doing 10 ppm at a time is because we will not know how much CYA you are starting with and don't want to overshoot 30 ppm by much.

Since we added CYA already, does that change the amount of liquid chlorine I should be adding and expecting to hold after 30 mins?

No, that CYA may have been eaten by the ammonia. Test with 10 ppm.

Finally, I will be able to add every 30 minutes tomorrow, but Monday is back to work. I can test and add chlorine before work, but no one will be available for 8 hours. Should I add more chlorine based on that? How many days is it expected to take to hold > 3 ppm?

Depends if you have an ammonia problem, how bad it is, and if you have enough liquid chlorine to break the ammonia cycle. Do the best you can.

 

[CrystalRiver]

What ajw is hinting at, is there is a bacteria that eats CYA and produces ammonia. Ammonia burns through chlorine quickly. If you have this bacteria in your water, you do not want to add more CYA until that bacteria is gone (as shown by holding FC for 30 minutes). Any ammonia in your water will quickly turn FC into CCs.

When we see a pool with low/no CYA, can't hold FC, and high CCs, we are quite suspicious about that bacteria being in the water.

 

[ajw22]

The ammonia problem is further explained in Ammonia - Further Reading

 

[JGenova]

Interesting. Based on that, I suspect ammonia as well, as I assume the previous owner was using trichlor tabs since there were some left over in the pool shed. I expected the opposite CYA problem (too high).

If I do have ammonia, would it be inadvisable to hit the problem hard and shock with 10x the CC, then switch back to SLAM or balancing the water? Sorry if that is a stupid question, I am very new to this.

 

[ajw22]

If I do have ammonia, would it be inadvisable to hit the problem hard and shock with 10x the CC, then switch back to SLAM or balancing the water? Sorry if that is a stupid question, I am very new to this.

No, please follow our process. It is proven to work.

 

[JGenova]

I will, thank you. Kicking myself for adding the CYA now.

I tested CYA and it went up to 40 after adding the 5 lbs worth. Is it safe to assume that we don't have an ammonia problem, or does the bacteria break down CYA slowly?

Most recent numbers:
FC: .4
CC. 1.8

 

[MITBeta]

• Add 10 ppm of liquid chlorine to your pool
• Test your FC after 30 minutes
• Repeat until your FC holds > 3 ppm after 30 minutes
• Only then check your CYA
• Add 10 ppm of CYA at a time until you get to between 20 and 30 CYA
• Start the SLAM Process

 

[ajw22]

I will, thank you. Kicking myself for adding the CYA now.

I tested CYA and it went up to 40 after adding the 5 lbs worth. Is it safe to assume that we don't have an ammonia problem, or does the bacteria break down CYA slowly?

Most recent numbers:
FC: .4
CC. 1.8

You should still put in 10 ppm of LC and check after 30 minutes. Let's see how much FC you lose.

We can help you better if you log all tests and chemical additions in PoolMath and share the logs.

 

[DeanP66]

Also, use the 10 mL sample size for your chlorine test, one heaping spoonful of powder and then count each drop as .5 ppm. You will save a lot of reagent that way. Since you're going up to 10 ppm FC, you don't have to be as fine as .2 for each drop. No reason for it. .5 is good enough.