Time to replace sand?

[PoolDoc]

The ingredient you listed is a mix of EDTA (a chelant) and ammonium sulfate. Adding ammonia according to the instructions you followed produces monochloramine. MonoC is very effective against algae, but also rather irritating. It's going to take a LOT of chlorine to get rid of it.

Also, you have very high TA due to the soda ash (borax would have been a better choice to use with the "G to C", but I'm sure the store didn't tell you that!). And it looks like you've done a bit of lime softening (lowered CH), which means some of the cloudiness is probably calcium carbonate.

So . . . you need dose with 6 gallons of bleach each evening. Take a break if you have higher than 15 ppm the following evening. Continue to dose that way till your CC is below 1 ppm, and your chlorine levels will 'hold' overnight.

Also, you'll need to get that TA down. So use muriatic acid (gloves, glasses, pour close to the water, watch the fumes!) to lower the pH till you reach 6.8. Stop, and wait for the pH to climb above 7.0, then repeat. Continue till your TA is below 100 ppm. The process will go faster if you adjust your return eyeballs so they 'ruffle' the water's surface.

Once you get done with those two things, you can decide whether you want to drain and refill, or run high chlorine. Personally, I'd run high chlorine.

Good luck!

Ben

[jonno]

The pool failed the overnight test. This morning FC = 0.5 TC = 5.5, pH = 7.2, TA = 190.
Thanks for the information about lowering the TA Ben. My return is ruffling the surface and I'll pick up some muriactic acid today. I'll also stock up on bleach.

Ben - can you clarify your instructions:
1. Add 6 gallons of bleach nightly until I get 15ppm the next evening - is that FC or TC?
2. Continue that way until the CC is below 1ppm - does that mean that FC and TC should be within 1 ppm of each other?
3. Get that TA down with muriatic acid until pH is 6.8. Wait for pH to climb above 7.0, then add another dose of muriatic acid - how long should i wait between tests? how much muriatic acid should I add for each dose? 1 cup for a 26K gal pool? Follow instructions on muriatic acid container?

Watermom (and Janet) - the priority in your instructions seems to be to get the chlorine to 25 and keep it there. The 17 gallons of bleach I added last night only got the FC to 4.0 and this morning it has dropped to 0.5. Here are my questions on your instructions:
1. You advised me to test as many times a day as possible and bring the cl back up to 25 each time (so the FC = 25 right?). I'll add another 17 gallons this morning, but how long should I wait after adding the bleach to see if I've reached 25? If not, I should add more bleach immediately - right?
2. You said to keep pH above 7.2, but Ben says to follow the steps lower the TA - should I do that now or wait until the FC passes the overnight test by holding within 1ppm of 25?

[Watermom]

1. FC
2. Yes.
3. I would try a pint of muriatic acid at a time. Wait a couple of hours, then retest pH and see how far it moved. If not low enough, add another pint and repeat.

1. Follow Ben's bleach dosing instructions instead.
2. Follow Ben's directions to lower alk.

You can read more about lowering alk here:

http://www.poolsolutions.com/gd/lowe...p-by-step.html

[jonno]

Thanks. I think I've got it. Here's the plan:

Get the TA down with muriatic acid until pH is 6.8.

1. Add 1 pint of muriatic acid, wait 2 hours and retest pH. If not 6.8, add another pint of muriatic acid, wait 2 hrs, etc.
2. Continue to aerate as this will lower the TA and raise the pH.
3. Keep testing pH and TA. Maintain pH at 6.8 (adding 1 cup to 1 pint of muriatic acid as needed).
4. Once TA reaches 120 (currently 190), let pH increase to normal level (7.4-7.6). If this does not happen within a couple days, add small amounts of borax to bring it up.
5. Once TA = 120 and pH is 7.4-7.6, stop aerating.

While lowering the TA, test FC and TC nightly.

1. Add 6 gallons of bleach nightly.
2. If FC = 15ppm from the previous night’s dose, skip the bleach for until the next evening.
3. Repeat this nightly until the CC is below 1ppm (FC and TC are within 1 ppm of each other)

Couple more questions:

• Am I missing anything in the steps above?
• Should I wait at least two hours after adding muriatic acid before adding the nightly dose of bleach?
• For my 26K gallon vinyl IG pool, how much is "a small amount" of borax? 1lb?

Thanks for the support, instructions and education! This morning I could just make out the second rung of the ladder so the visibilty is starting to improve. I'll keep you posted via this thread. -- John

[aylad]

Looks like you pretty much have it under control, your plan of attack looks good to me.
Regarding the 2 hours wait period after adding acid--if you're waiting to see what the resulting pH is after the acid addition, then you probably should wait the 2 hours, because it can take that long for the acid to be distributed evenly in the pool, and you'll sometimes get a falsely high pH reading if your chlorine is high from the large bleach addition. However, if you already know where that's going to put your pH, and you're just concerned about the safety of adding the chems that close together, waiting 2 hours is not really necessary. I add mine in front of a return, pouring very slowly, and usually wait 15-20 minutes before following up with bleach.

Regarding Borax, since you want to make very small additions, I would start with a couple of cups at a time. Add it very slowly through the skimmer, breaking up any clumps, give it time to dissolve and circulate ( a couple of hours is enough) and then test and add more if necessary.

Janet

[jonno]

Early this morning I put in about 12 gallons of bleach, but by 7pm this evening the FC = 0 and CC = 4. I guess sun burned it all up.

This evening, I put in a pint of muriatic acid and about 20 minutes later put in 6 gallons of bleach.
Two hours later I tested and got the following numbers;
FC = 5.0
CC = 7.0
pH = 7.0
TA = 190

I'll stay with the plan, but please let me know if I should change amounts or vary any of the steps.

• Since 7.0 is the lowest level measured by the K-2006 should I leave the pH or add another pint of muriatic acid?
• Should I be brushing the walls/bottom or try vacuuming (I still can't see the bottom)?

Many thanks!

[aylad]

I don't think the sun burned it up...more likely, it was eaten up by the ammonia from all the junk the pool store had you put into the pool. Ammonia can cause quite a huge chlorine demand, but it's going to have to be overcome in order to get your pool back under control.

If the pH reading you got was a solid 7.0, then I would go ahead and add another pint of acid. If it was any lighter, then I would wait until the pH climbs a little bit--but then I'm pretty conservative when it comes to acid use. Brushing the walls daily would be a good thing to do, but I wouldn't try vacuuming yet, since you don't know what's at the bottom, and it will just waste water that you're trying to adjust. You might try scooping anything you can off of the bottom with a leaf net, though.

Janet

[jonno]

The pH was a solid 7.0, so I'll add another pint of acid tonight and I'll start brushing the sides daily and scoop leaves that I'm sure are hiding on the bottom.

I'm sure you're probably right about the ammonia eating the chlorine Janet. I had dumped a gallon of cheap algaecide in the pool over several weeks when I opened the pool so I was also an agent of harm.

• Given the need to eat up all that ammonia should I add more bleach than the 6 gallons nightly that Ben prescribed?

Thanks again.

[aylad]

Asking Ben about this now...it would seem to me that the chlorine needs to be higher, but he may have a reason why he doesn't want to elevate it. Hopefully I'll either get an answer soon or he'll pop by and update this himself...

Janet

[jonno]

Here are tonight's numbers:
FC 0.0
CC 3.5
pH 7.0
TA 210

Added 1 pint acid, brushed walls and bottom for 20 minutes or so, then added 6 gallons of bleach. I can just make out the brushhead when it is on the bottom in the shallow end so the visibility is slowly improving. At first I wondered why the TA increased from 190 to 210, but then realized I had a slow trickle of water running in over the past three days to bring up the level about 3" as the skimmer had started to suck air after backwashing this weekend. I tested our household water and the TA = 160, pH = 7.1. Our source is a spring/cistern that runs through a calcium carbonate & magnesium oxide acid neutralizer.

Thanks Janet - I'll stand by for Ben's response. Stocked up on bleach today...