Pool turned green and they got pool stored, time to help!

[JesseWV]

A friend of mine has an A/G 20'x48" which specifies it holds 7900 gal. It has a SWG, [s:2nx5ct9t]probably Intex[/s:2nx5ct9t] Krystal clear. The water recently had an algae bloom and turned green. She took her water to the pool store and her test results were very thorough:

FC: 0.0
TC: 0.0
CC:0.0
pH: 7.6
TA: 239
CYA:5
TH:0
Salt: 3100
TDS:610
Copper, Iron, Phosphate, Borate, Nitrate, Biguanide, Biguanide shock: ALL = 0

She was told buy the pool store to put a total of 1 gallon of Muriatic Acid to bring down the TA. They instructed her to add 1 pint of MA every half hour until gone. She was slso told to add 2 lbs shock, which I assume was dichlor. Then wait 1 hour and add 2 oz of AlgaeZone Plus.

AlgaeZone Plus is:
Copper triethanolamine complex 82027-59-6 7.1%
Alkyl dimethylbenzylammonium chloride 68424-85-1 2.5%

They've run the filter continuously for 24 hours and the SWG is set to run 4 hours a day. The water is blue, but it's still cloudy. They can see the bottom of the pool if looking straight down.

The pool store told her if she still had green on Monday to shock and AlgaeZone again, but there is no green and the walls are not slippery/slimy.

--- The above information was transposed from a Facebook conversation. I will be inviting her to join us here for further assistance ---

 

[Bama Rambler]

Re: Pool turned green and they got pool stored, time to help

They need to get the FC up with bleach until they figure out what's going on. I suspect they need to shock and they should use bleach to do that.

I also suspect the pool store numbers are wrong, i.e. they list the salt at 3100 but the TDS (which includes salt) at 610.

 

[DanielleW]

Re: Pool turned green and they got pool stored, time to help

Ok I would be the friend with the pool issues!

We put the pool up about 2 weeks ago. I bought a salt water filter (Krystal clear) to go along with my pool from walmart. We set it up according to the directions and enjoyed the pool for about a week! I used the little paper test strips (which I'd never used before) and I was getting wacky readings so I figured I'd better take it to a pool store. 2 days before I took a water sample to be tested (please understand I live in a little town so everything is a drive, so you don't just pick up and go, you plan ) I noticed it was turning kind of green. I knew then I had issues!

Jesse posted the readings from the pool store and what I was told to do.

Here is where we stand now! My water IS blue, but cloudy. The filter has been running continously for over 24 hours, with the SWG running for 4 hours a day (which I was told would be sufficent for the size of my pool).

Jesse suggested I take a reading with the test strips again (is this the best method to be testing my pool water with? If not what should I go buy to get the best readings.. I was a lifeguard in HS and college but never had to test more than just the pH and cholorine) and take a picture and post it here. Would that be better? We have company coming Wednesday and I'd LOVE to be back swimming in our pool!

 

[zea3]

Re: Pool turned green and they got pool stored, time to help

Hi Danielle, welcome to TFP! Have you put any chemical in your pool other than salt and the salt water generator?

 

[DanielleW]

Re: Pool turned green and they got pool stored, time to help

The only chemicals we have put in there was pH minus and 6 oz of algea 3x concentrate (HTH brand) on Friday as we had high pH (according to my test strips) and algae! I called the 1800 from our pool instructions and that's what they instructed.

On Saturday I realized we had more of a problem and I decided to take the water to best tested. The test results are listed above and we did 1 gallon of muraitic acid to b/c we had high alkalinity, 2lbs of shock and then 2 oz of algaezone Plus. Since then we haven't added anything else to the pool.

~danielle~

PS I did take the pool brush and brushed the sides and bottom of the pool and we've replaced the filter cartridge. It is now blue, but cloudy!

 

[DanielleW]

Re: Pool turned green and they got pool stored, time to help

When we put the pool up, we added 3 40lb bags of salt to the pool (we have about 7900 gallon pool). This is my first go at a salt water pool!

~danielle~

 

[JesseWV]

Re: Pool turned green and they got pool stored, time to help

Here is where you are now:

You've added 1 gal (128oz) of Muriatic Acid which will indeed reduce your TA. However it also reduced your already near perfect pH from 7.6 to 6.7. The pool store neglected to tell you that you need to raise the pH back around 7.5.

There are two ways do this:

1) Aerate the water by adjusting your return jet eyeball upward toward the surface of the water so it churns air into it. It may take a few days but it's free!
2) Add 20 Mule Team Borax from the laundry isle. My calculations say 244oz by volume (measuring cup) or 254oz by weight.


Now for the Chlorine. You've added 2 lbs of dichlor. This would have raised your FC to 17.

Adding the dichlor shock also increased your CYA by 15 to from 5 to 20. This is a decent starting point for CYA. We'll remember this value for later when you're done shocking and start getting CYA up to the proper level for a SWG, salt water (chlorine) generator.

The cheapest way to shock your pool is with liquid bleach also from the laundry isle. Only the name brand or generic unscented regular bleach is suitable. Don't get anything that says "Outdoor" or "Splashless." The only ingredient in it should be "Sodium Hypochlorite." It should also list the percentage, 6.0% is the most common. I know Walmart has 182oz jugs for $2.54 here.

The algaecide you added is copper based. This will help to prevent algae from starting to grow in a clear pool but does little to actually kill algae.
Do not get in the habit of adding this when you see algae starting. It can turn your blonde hair green. Just hit it with some bleach to shock level and you will stay golden, literally.

You can test with the strips you have for now while the pool store is closed. When they reopen I would take another sample in to get tested to confirm these calculations, then we can go from there.

Do not add anymore dichlor (shock) at this point. We'll use that when you're almost done shocking with bleach. Unstabilized chlorine bleach is much more effective at killing algae.

I would start by reading through Pool School The kit you need is the TF-100 it will allow you to read everything you need to keep your pool clear and sparkling all summer. It will also save you from spending a lot of money at the pool store.

 

[DanielleW]

Re: Pool turned green and they got pool stored, time to help

I actually have the return "eye" pointed upwards. It allows me to see when the filter is running (and check it if it's supposed to be for low flow) from the kitech window!

I'll take a sample tomorrow to get it tested and post my results. I wont buy anything this time though b/c bleach is cheap (I have coupons for it)!

I will also look into get the test kit you suggested b/c I dislike those strips as I feel I'm not getting accurate readings!

~danielle~

 

[JesseWV]

Re: Pool turned green and they got pool stored, time to help

I actually have the return "eye" pointed upwards. It allows me to see when the filter is running (and check it if it's supposed to be for low flow) from the kitech window!

I'll take a sample tomorrow to get it tested and post my results. I wont buy anything this time though b/c bleach is cheap (I have coupons for it)!

I will also look into get the test kit you suggested b/c I dislike those strips as I feel I'm not getting accurate readings!

The more air churning into the water the better. The strips do suck. I've dealt with them and they can cause trouble. I hesitate to say this but I suppose they are better than nothing as long as you don't take any drastic actions adding chemicals to the pool based on the strip readings.

 

[zea3]

Re: Pool turned green and they got pool stored, time to help

The only thing I would add at this point is to turn off the SWG until you complete the shock process. No need in running it while you are shocking with bleach. That will save a little wear and tear on the cell.

 

[JesseWV]

Re: Pool turned green and they got pool stored, time to help

The only thing I would add at this point is to turn off the SWG until you complete the shock process. No need in running it while you are shocking with bleach. That will save a little wear and tear on the cell.

Good idea. It might be worth testing the water with the test strips before bed tonight. We want make sure the FC level is still off the scale. If it's not she may as well add some bleach to keep it in check over night.

 

[duraleigh]

Re: Pool turned green and they got pool stored, time to help

This thread points out one of the unique teaching points first introduced by Ben Powell on his forum and carried forward here.

You can only PERMANENTLY lower TA with the combination of acid and aeration. If you do it any other way, you get into the yo-yo effect that DanielleW experienced. The details of how to lower TA are found in Pool School but this is handy to remember....

To lower pH - Use muriatic acid...TA comes down also (but goes back up if pH goes up)
To raise pH - Use 20 mule team borax. It has little affect on TA

To raise TA - use baking soda - it has little affect on pH
To lower TA - use the acid/aeration method deascribed in Pool School

 

[DanielleW]

Re: Pool turned green and they got pool stored, time to help

Ok I went and head my water tested again this morning! Here's the newest set of results!

FC 0.0
TC 0.2
CC 0.2
pH 7.2
Hardness 10
TA: 237 (it was 239!!)
CYA: 10
copper 0.2
Iron .4
TDS 610
Salt 3300.
Phosphate, Borate, nitrate, biguanide and biguanide shock all 0.
Water temp is 70.

I was instructed to do another round of Muriatic acid (1 gallon = 1pint every 30 minutes until gone). Wait 30 minutes and then do 1 1/2lbs of Shock.

I know my TA is still high and my TC is still low. LOL. Suggest away The water is still a little cloudy, but blue. I can see more of the bottom today than I could last night. The walls are not slippery/slimy either. The filter is still running continously and the cartridge was changed on Saturday.

~danielle~

PS I DO have the eye of the return jet pointed upwards so it creates bubbles/stream affect in the pool. I DID buy the acid and shock as it's not something I can get easily here in town. I can go get bleach if that is better to try.

 

[Bama Rambler]

Re: Pool turned green and they got pool stored, time to help

With your pH at 7.2 you don't need to be adding acid until it comes up. I'd go ahead and shock, but you need to shock according to pool school.

 

[DanielleW]

Re: Pool turned green and they got pool stored, time to help

Ok I will not do the acid today. I'll go ahead and shock it. I don't have the means to do the overnight test yet to see if it's loosing cholorine though.

Right now I currently only have test strips (we will be purchasing a better kit on Friday- payday). I'm not 100% sure I'm getting accurate readings with the test strips though.

Thank you!

~danielle~

 

[Bama Rambler]

Re: Pool turned green and they got pool stored, time to help

Just do the best you can until you get a better kit.

 

[DanielleW]

Re: Pool turned green and they got pool stored, time to help

Thank you

 

[JesseWV]

Re: Pool turned green and they got pool stored, time to help

I was instructed to do another round of Muriatic acid (1 gallon = 1pint every 30 minutes until gone). Wait 30 minutes and then do 1 1/2lbs of Shock.

I second what Bama said. You don't want to mess with your pH or TA right now. You do want to start the shock process.

The water is still a little cloudy, but blue. I can see more of the bottom today than I could last night. The walls are not slippery/slimy either. The filter is still running continously and the cartridge was changed on Saturday.

At least you're making progress. Filtering dead algae with cartridges can clog them up quick so they'll need to be cleaned often. Also they can get expensive over time when they need replaced. A cheap sand filter will save money in the long run.

PS I DO have the eye of the return jet pointed upwards so it creates bubbles/stream affect in the pool.

If a decent amount of air is being introduced you should see a rise in pH on your test strips. We'll see how much it has changed after shocking is complete and your FC comes down from shock level to target level.

I DID buy the acid and shock as it's not something I can get easily here in town. I can go get bleach if that is better to try.

If you have a hardware store in town you might want to check in the paint section there for Muriatic Acid (paint stripper.) Bleach is the best and cheapest way to shock most of the time unless you can find cheap chlorinating liquid at a pool store.

I know my TA is still high and my TC is still low.

Your TA is high but that can wait until you get your FC to hold.

What does the package of "shock" list as ingredients? I've been assuming it to be Dichlor (dichloro-s-triazinetrione.) We recommend that you do not use this to keep the water at shock level. Dichlor adds CYA which increases the required shock level. Stopping the use of dichlor now will make it possible to roughly maintain shock levels of 11 FC using your test strips if they measure up to 10ppm FC like most.

You really need to shock with bleach anyway. Save the dichlor for after your done shocking and it won't be wasted. You can "kill two birds with one stone" at that point. You can use it to maintain your target FC levels until your CYA hits the recommended SWG level of 80-90. Then all you'll need to do is turn on your SWG. Then you can begin getting your TA down.

To begin the shock process add 182 oz of 6.0% liquid bleach after sundown. That'll get you to 11ppm FC. If you see the FC test looking lighter than the darkest 10ppm shade on the scale you'll need to add more bleach to keep it holding over 10.

 

[DanielleW]

Re: Pool turned green and they got pool stored, time to help

I already put the shock in before I read the post. LOL. Figures!

I'll get some bleach tomorrow and do that tomorrow night. I am also going to see if I can get a basic test kit until we can get the better one. I just worry about my test strips!!


How long do I need to maintain the chlorine lvl above 10ppm? So if I do it tomorrow night after sundown, test it and then test it again early Wednesday morning and it's still above 10ppm, I'm ok, correct? If it drops, I need to repeat again on Wednesday night? I want to be sure I understand this correctly!

Thanks!

~danielle~

 

[DanielleW]

Re: Pool turned green and they got pool stored, time to help

And how long after I put in the bleach do I need to wait to do the test? I know, so many questions! I just worry with having young kiddos swimming in the pool. I cringe when I look over at the neighbors and see all the green in their pool yet their kids are swimming! ICK!

~danielle~