Time to replace sand?

Hi everyone - my first post, please help.

Short story: Started putting in algeacide, but water stayed green. Put in 1 gallon over 3 weeks (I didn't know that it is a preventative and that only chlorine kills algea - now I know).
Spent 3 weeks, shocking, brushing, putting a little Fiber Clear down skimmer, but pool stayed very cloudy (visibility less than 20") and green.

I bought the Taylor water test kit through the link from this forum. This mornings numbers are:
Free Chl: 3.2
Avail Chl: 2.2
pH: 7.2 (then I added 6 lbs soda ash per the chart)
Ttl Alk: 180
CYA: over 100
Calcium Hardness: 160
Other measurements from pool store last Thursday:
TDS: 1500
Phosphates: 0

Last Thursday (my 5th trip to the pool store), they told me to do the "Green to Clean" treatment. Backwash, Boost pH to 8.0 (added 8 lbs of soda ash to do this), wait 4 hrs, brush sides and bottom, add "Green to Clean" and 4 lbs shock, wait 12 hrs add 4 lbs shock (repeat shock two more times, waiting 12 hrs each time).

It finally turned my water from green to blue, but water is milky/cloudy. My hand disappears as soon as the water is past my elbow.

Pool is 26,000 gallons, vinyl liner, sand filter (275 lbs sand). Water is about 10 years old, sand is about 6 years old. The pressure does not vary much before/after backwash.

I will change the sand this weekend. But I want to run this by the experts - Is there anything else I should do? Is the water safe to swim in now?

Many thanks! John

Quote:

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Originally Posted by jonno

I will change the sand this weekend. But I want to run this by the experts - Is there anything else I should do? Is the water safe to swim in now?

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Stay out of that pool store! You've been what we call around here "pool-stored."

Your CYA is 100 which is very high. The bad news is that test kits cannot differentiate past 100 so in all reality, it could actually be a lot higher than 100. You have a couple of options:

1. Do a partial drain and refill and try and lower that CYA level. Do NOT totally drain your pool however. You should be able to safely drain 2/3 of the water, though.

OR

2. Run higher than normal chlorine levels to compensate for the high CYA. Take a look at the Best Guess Chart link in my signature below for needed levels.

A couple of other things you'll need to do if you decide NOT to do a partial drain and refill:

Your alk is high at 180. After your pool clears, you'll want to try and lower that some. Don't use anymore soda ash to raise pH because it is raising alk at the same time. Instead, use 20 Mule Team Borax (laundry aisle at Walmart) to raise pH.

Also, I'd suggest shocking the pool up to 25 and try and hold it at that level until you can go from sundown one evening til sunup the next morning without losing more than 1ppm of chlorine. At that point, you can let the cl drift down and keep it between 8-15 ALL the time or risk an algae bloom. You should also be running your pump 24/7 while you are trying to clear this up.

Also, please get a good test kit. Click on the Amazon link in my sig and get a Taylor K-2006 or 2006C which is the same kit with a larger quantity of some of the most used reagents. Buying through that link makes the Pool Forum a little money on the sale which helps keep us online. Only buy if the seller is Amato Industries. Some other sellers are substituting the K-2005 which you do NOT want. You'll need the good kit regardless of whether or not you drain and refill or not. But, if you do NOT drain and refill, you MUST buy it or else you won't be able to measure the high cl levels you'll be required to run.

Hope this helps. Let us know your preference between option 1 and 2 and we'll help you go from there.

EDIT -- Almost forgot. You do NOT need to change your sand. My sand is 11 years old and many other people have sand much older. Don't bother changing it.

EDIT again -- to add a link about lowering alk. Don't worry about this yet if you decide to do that partial drain/refill.

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

EDIT yet again! Because I forgot to welcome you to the forum and also to say thank you for becoming a subscriber. Subscriptions help us be able to stay online!

I have been fighting the same problem off and on for years. What I discovered is that I had lost a little sand over a few years and the filter was not working correctly. When changing the sand last week I noticed that there was more than I had removed. Pool water is much better now.

I'm gonna rig up some unions ( I used regular couplings last time) so that I can pop the top off the filter and add a bag or two of sand per year. Either that or switch back to a DE filter.

Thanks watermom and thegoose. Can you tell me if the water is safe to swim in? (Family really wants to swim!) I used the Taylor K-2006 kit to get the numbers reported above.

I expect the CYA is off the charts because that black dot disappeared way before water reached the 100 level in the small tube.Before doing the "Green to Clean" treatment last week, the CYA level was 30 and the Ttl Alk was 90. Since it was very cloudy before the sky-high CYA and Total Alk, the "Green to Clean" treatment killed off the algae but caused these high CYA/Ttl levels. I'll recheck the water tonight to make sure I did it correctly.

I'll shock the pool to 25 ppm - what kind of shock should I use to do that and how can I figure out how much to use. I'll also keep the chlorine high for now and see if I can rig up a aeration. I'll also check the sand level and make sure the pipes in the filter are in good shape.

By the way, draining and refilling 2/3 of the pool, will cost $800 just for the water. The vinyl liner is already 13 years old and getting harder to keep the beads seated in the coping. Pretty soon I expect that I'll have to replace the liner so, it would make sense to replace the liner and replace the water at the same time -- but I can't afford to do that (both kids in college).

Any other advice is most welcome! Thanks again - John

For a CYA over 100, you need to be keeping your chlorine levels between 8 and 15 ppm at all times to keep the algae away, so you need to get some chlorine in the pool ASAP or you're going to undo all the work you've done. In a 26K gallon pool, each gallon of 6% bleach that you add will raise your chlorine by just over 2 ppm, but not quite 2.5, so you can use that as a guide. Since your CYA is already high, I absolutely would not advise you to use dichlor powder or trichlor pucks in this pool, as the CYA will just keep climbing through the roof. I would use plain, generic, unscented, household bleach. Check the label, make sure it's 5.25 or 6% in strength.

Generally we recommend maintaining the shock level until you're not losing any chlorine when testing at night and again in the morning before the sun hits the pool (to rule out any chlorine loss due to sunlight). There is no danger to you or your family from the algae, per se, but if there is algae growing in the pool, then that means there's not enough sanitizer present to kill off any other viruses or bacteria that may be in the water. Also, with a cloudy/milky pool, there is a very real danger to anybody that gets into the deep end and is having trouble but cannot be seen by others around the pool. I would wait to swim until you can at least make out the bottom, and until you're not losing any chlorine overnight. At that time you can let your chlorine levels drop to normal, but never less than 8 ppm as long as your stabilizer is that high.

Aeration can be done via fountain, splashing kids, or just by pointing your returns upwards so that they cause a ripple in the water.

Janet

Is the pool still green or only cloudy now? What is the ingredient in "Green to Clean?" I can't imagine that it could cause your CYA to go up from 30 to maybe 100+. Maybe the test result was read incorrectly the first time. Also, retest your chlorine and get a FC and a CC reading for us.

In your pool, each gallon (4 quarts) of 6% bleach will add 2.3ppm of chlorine to the water. Use that to help you determine how much bleach to add each time you test to take the cl back up to 25ppm. Have you done the overnight test? That is where you test the chlorine in the evening after the sun is off the pool and then again within two hours of sunrise to see if you are losing more than 1ppm of chlorine. If you do, then you are still fighting something in the water and need to continue shocking.

I know your family is anxious to swim, but we need to be sure things are safe before recommending that you let them in the pool.

I understand about not wanting to drain. Just run higher than normal chlorine levels after you get this cleared up and you'll be ok with the high CYA. Don't add anything else to the pool right now except for bleach to get to 25. (Except for some Borax if your pH drops any below 7.2.) Test as many times a day as you can and each time get the cl back up to 25. There is no such thing as testing and dosing too often when you are trying to clear a pool. The more times a day that you do so, the faster it will clear up. Run the pump 24/7.

EDIT --Apparently Janet posted while I was typing, but our advice is basically the same.

The pool is no longer green - it is only cloudy now.

Here is the pool when it was green: http://www.flickr.com/photos/3521519...in/photostream
Here it is last Saturday when it finally turned blue: http://www.flickr.com/photos/3521519...n/photostream/
Here is a close-up to show the unchanged poor visibility: http://www.flickr.com/photos/3521519...n/photostream/

When I get home tonight, I'll check everything and report back. I'll also pick up a bunch of 6% unscented bleach and borax and add it to bring up the chlorine to 25 and do the overnight test.

I don't know what is in "Green to Clean." Here is the link to the product page, but, mysteriously, they do not disclose the active ingredient. http://www.green-to-clean.com/FAQ.html

Found the ingredients to Green to Clean - it is "Disodiumsalt of ethylenediaminetetraaceticaciddihydratediammoniums ulfate
100% (active ingredient)" Here is the link to the MSDS.

I know nothing about Green to Clean. Post current readings and tell us of any changes in the water quality.

Here are this evening's numbers:
FC 0.5
CC 1.0
pH 7.2
TA 190
CH 130
CYA over 100

I opened the filter, stirred up the sand and backwash out lots of gunk.
Then added 60 lbs of sand to bring it up to the right level.

I pointed the return upward and now have a small standing wave rippling the surface.

I added almost 11 gallons of 6% bleach (7.5 jugs each with 1.42 gallons) and tested the water about an hour later.
FC = 4.0
CC = 6.5

Using the formula of 1 gal. increases chlorine by 2.3 ppm, this amount of bleach should have brought the chlorine up to 25. I added the remaining 6 gallons of bleach (4.5 jugs) and will test in the morning. If the 1 gal = 2.3 ppm applies, then this will only bring me to 21 ppm, but I'm out of bleach, it's late and time for bed. I'll test in the morning and report in.

My pH is 7.2 and it took 10 drops to bring it up to 7.4. Should I add a box of Mule Team borax now or wait until after the chlorine passes the overnight test?

Thanks!

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

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?

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

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

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

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!

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

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.

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

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...

Morning report:
FC 0.0
CC 4.5
pH 7.2
TA 200
There's a small amount of airy foam on the surface for the past couple of days - I imagine this is from the return riffling the surface, but I mention it here in case there is a larger significance. Since the pH has risen, I'll get some more acid today to keep it at or below 7.0.

The foaming could be from the algaecide you added. That is a common side effect. (Also one of the reasons that the only algaecide we recommend is Polyquat 60%.)

Ben's response was to stick with the 6 gallon bleach doseage that he initially recommended. With large amounts of ammonia to break down, you're going to have higher than normal combined chlorine to deal with, that can be very irritating and uncomfortable. So..his recommendation was to break it down slowly with the lower doses of bleach, until you start getting CC readings of 1 or 2--at which time you can up the doseage and go ahead and get rid of it. So...stick with the 6 gallon dose for now.

I agree with Watermom on the foaming--it's likely evidence of the algaecide breaking down. Stay the course the way Ben recommended--and we'll help you get it cleaned up!!

Janet

Roger that and thanks! I'll stay the course and keep posting my numbers.

Evening report:
FC 2.3
CC 0.4 (tested twice to confirm both FC and CC)
pH 7.2 / 7.4
TA 190
After pulling the water sample, I added 1 pint acid, brushed the walls and bottom. Visibility unchanged over past two days (about 2'), then added 6 gallons of bleach. Still have scattering of light foam on the surface.

Since the CC was 0.4, I should up the bleach according to your post earlier today. How much?

Do you have any guess at the timeframe until this treatment clears the water up - days weeks?

I have questions about maintaining the pool with CYA so high (somewhere way over 100), but I'll wait until I get to that point before asking. Thanks!

Disregard yesterday evening's water tests! I messed up. Here are the morning numbers:
FC 0.5
CC 3.5
pH 7.2 / 7.4
TA 180
Since the pH is still up, even after last nitght's pint, I'll add another pint of acid this morning. No change in visibility. Still have scattering of light foam on the surface. Water is starting to look more green than blue - could it be another algae bloom?

Remember to approach adding chemicals conservatively. Usually, bleach/chlorine is the exception but given your unusual circumstance even that should be done with care. Your FC is down so you need to raise it to the level Ben recommends.

Carl

Thanks Carl. Ben's chart shows that given my CYA of 100 to 200, my FC level should be 8 to 15 ppm). However, I have a lot of ammonia so Ben gave me a treatment plan to follow until the CC is down to 1 or 2. The interim plan is to add 6 gallons of bleach every evening, add a pint of muratic acid when the pH creeps above 7.0, and keep aerating.

Evening numbers - pool color is changing from blue to yellow green!
FC 0.0
CC 3.0
pH 7.2
TA 180
I added another pint of acid this morning and will get some more tomorrow to keep the pH low, but today the color of the water no longer has any blue coloration and is more lemon lime. Visibility is still only 20-24 inches. This is nerve-racking. I really don't want to replace the water. Ben, Janet, Watermom - is there anything else I should be doing?

Morning report - color still yellow green, little bit of foam on surface. Still aerating and adding 6 gallons of bleach nightly.
FC 0.0
CC 2.5
pH 7.2
TA 180
Happy Father's Day everyone who is or has a dad.

POPP! Pool Owner Patience and Persistance!

Carl

Evening numbers:
FC 0.0
CC 2.0
pH 7.3
TA 180
Headed out to get more acid to keep the pH at 7.0, but glad to see that the CC finally is in the 1 - 2 range. Thanks for the reminder about POPP Carl.

On 6/17 Janet wrote:
"So..his (Ben's) recommendation was to break it (the ammonia) down slowly with the lower doses of bleach, until you start getting CC readings of 1 or 2--at which time you can up the doseage and go ahead and get rid of it. So...stick with the 6 gallon dose for now."

This is the 2nd day that my CC was 2 or lower. Is it time to up the dosage of bleach?

Here're this evening's numbers:
FC 0.0
CC between 1.5 and 2.0
pH 7.4 (put in 30 oz dry acid)
TA 190

Thanks!

If you want to go to a 9 gallon dose, that would be OK.

If you can, use muriatic instead of dry acid. It's cheaper, stronger, and better for your pool. Of course it's more noxious to handle -- gloves, glasses & watch the fumes when you pour! But you're going to need to lower your alkalinity, so keep pushing the pH back down.

Thanks Ben - I'll up the dose to 9 gallons starting with this evening's dose.
FC 2.5 (first time I've seen FC in a while)
CC 2.0
pH 7.3 I switched back to muriatic acid this morning.
TA 190-200

Evening numbers:
FC 0.5
CC 1.5
pH 7.2 (put in more m. acid)
TA 180

Tonight the dosage increased to 9 gallons of 6% bleach - water is quite green, visibility about 20"
Ordered a couple 5 gal carboys from Uline and found a local cleaning supply that sells 12.5% bleach for $2.75/gal. so I can keep up the dosage until the water clears - it will seem like alchemy when it does!

Morning report:
FC 10.5
CC 2.5
pH 7.2 (added more acid)
TA 190
Water still green with low visibility.

Here is a photo of my pool taken this morning. This is the BEFORE photo.

I've spent the past two weeks working to eliminate the excess ammonia and lower the TA - this was not a process where progress is visible.

Now that Ben has increased the evening dosage of bleach to shock levels (considering my high CYA), there should be some visible progress as the algae and visibility problems resolve.

I'll post an AFTER photo as soon as everything is balanced and clear. This is day 33 since opening the pool - wish I'd never gone to the pool store...

http://i160.photobucket.com/albums/t..._IMAGE_162.jpg

Evening numbers:
FC 4.0
CC 2.0
pH 7.2 (added 1 pint of m. acid)
TA 170
Evening bleach dose = 9 gallons

Morning numbers:
FC 18.5
CC 2.0
pH 7.2 (added another pint of m. acid)
TA 180
This morning the FC was much higher than in the past and I think it may be affecting the TA test. Today the TA test water turned from green to briefly bluish to pinkish. All other days the TA test water has changed from green to briefly purple to a deeper red.

The pool water has a little more visibility (almost 30") and the shade of green is lighter so the shock is attacking the algae and POPP seems to be paying off.

The recycle man has dozens of bleach bottles to pick up this morning, but my 5 gal. carboys arrived last night and today I'm making my first run to fill them with 5 gal of 12.5% bleach.

• Given that my CYA is between 100-200, can anyone give me a ballpark estimate of how much bleach I'll be using each week to keep my chlorine in the 8-15 target zone (once my water is balanced and clear)?

I'm using a 9 gallons/day dosage now until the FC holds within 1 ppm from one evening to the next (once I switch over to 12.5% bleach, the 9 gallons will convert to just under 4.5 gal).
Thanks!