Cloudy water after filter change

First I just want to say thank you so much for teaching a man "how to fish." The pool stores just want to "sell me their fish." God forbid you ask them "why" you have to buy all those chemicals and put them in your pool. The knowledge I have learned on this site will last a lifetime (or at least until old age sets in).

So I opened my pool about 3 and half weeks ago. It is around 27,000 gallons/vinyl. I shocked it with 3lbs Power Shock (97% Sodium Dichloro-s-trianzinetrione) and added 1 bottle of Agicil (60% Poly [oxyethylene (dimethyliminio) ethylene (dimethyliminio) ethylene dichloride])...probably didn't have to type all of that out, but I want to be thorough.

After the water cleared up I vacuumed the pool and headed over to the pool store for a water test. At that time the water was on the cloudy side, but I just vacuumed and that probably kicked up some stuff that I figured the filter would catch.

Their results:
FC: 0 TC: 0.7 CC: 0.7 pH: 7.4 Hardness: 137 Alk: 106 CYA: 28

They told me to add 3lbs more of shock and another bottle of algaecide and fill my dispenser with Mini-Tabs (1in tablets of 99% Trichloro-s-Triazinetrione). They also gave me a Hardness Control which I did not end up putting in. The next day looked great (in retrospect it was not crystal clear like your Day 4 picture on the bleach demonstration, but it wasn't cloudy either).

After a weekend of swimming I shocked the pool again (3lbs). A couple of days later I noticed that I had a crack in my filter at the multiport valve where the return line came in. Since our old filter company went out of business (Jacuzzi) we decided to get a new filter (sand-Pentair SD80) rather than try to repair. Unfortunately I had to wait over a week to get it installed and the water became so cloudy that I could not see the bottom. After it was installed I shocked it with 3lbs and let the filter run for 2 days and there was no improvement. It also may be important to point out that I have an Aqua Genie skimmer which dispenses my Trichlor tabs with a spillover, so when the filter is not running, the dispenser doesn't work. In retrospect, I should have made sure that something was providing chlorine to my water, but not sure if that would have mattered without circulation. So I went to the pool store and got a water test and told them my problem.

Their results:
FC: 0 TC: 0.6 CC: 0.6 pH: 7.6 Hardness: 246 Alk: 65 CYA: 10

They told me to shock the pool again (3lbs) and add 6 capfuls of Alum (aluminum sulfate) to my skimmer as a sand filter aid. A capful is not much, probably 1/4 of a cup. They said that it may take awhile and to backwash my filter after the gauge goes up 10psi and repeat until the cloudiness is gone. Cloudiness did not change at all and my psi did not budge (maybe 1-2psi).

Since then I have been trying to consume as much knowledge on poolforum and poolsolutions as possible. Last night I got an OTO test and 7 bottles of 1.42G of generic bleach, some borax and baking soda from walmart. My chlorine test was clear, showing no chlorine. The pH was around 7.2. I added 4 bottles of bleach to raise the chlorine to around 10ppm. This morning I tested everything with my K-1005 kit that I bought last year (K-2006 is in the mail). I got the following:

FC: 1-2 TC: 5-10 (probably higher) CC: >8 pH: 7.2 Alk: 60 CYA: 0 (water was clear).

After the reading, I decided to raise the pH with 2 cups of borax this morning. When I got home from work the water still looks cloudy, but I feel like I can see further into the deep end. Here are my readings from tonight at dusk.

FC: 1-2 TC: 3-6 CC: 2-4 pH: 7.4 Alk: 60 CYA: 0 (water is clear).

Sorry for this ridiculously long post, but I wanted to give you ALL of the details. After reading through this site, I feel like I have never been more prepared to care for my pool, but first I need to clear this cloudy water.

I hope you can help.
Jim

There are many reasons for cloudy water, one of which is an impending algae bloom. With such a large difference in your FC and TC readings, and the long periods of time during which your pool wasn't getting chlorine, it looks like you're fighting something in the water. If it were my pool, I would shock the pool to 12-15 ppm and hold it at that level until there was less than a 1 ppm difference in my FC and TC numbers, and until I lose less than 1 ppm of chlorine when testing at night and again in the morning before the sun hits the pool. Keep in mind that shocking the pool doesn't mean raising the chlorine level just once--it means raising it and holding the high level until whatever you're trying to kill is gone, which can take a few days.

I would keep the filter running during the process, and brush the pool daily, preferably after chlorine additions, until it clears.


Welcome to the forum!!

Thanks, that makes sense. After another day of reading the site, my confidence level of being able to solve this problem is definitely going up.

I shocked the pool the last 3 nights with 6% bleach. I didn't think to keep those levels throughout the day because I figured the sun would burn it up. But going forward I plan on waking up at dawn and shocking again if necessary before the sun gets too strong. Should that be enough or do I need to be adding chlorine throughout the day?

I just got my K-2006 kit in the mail and I should be getting more accurate readings. I will post back my progress.

One more question: I have been shocking at 15ppm levels. Any benefit of shocking at higher levels? 30ppm? 50ppm? What are the downsides? I do have a vinyl liner. Is there a level that I should not got higher than for a vinyl liner?

Thanks again for your help. My spirits are definitely up.

Jim

The reason Jan suggested checking chlorine several times through the day and adding chlorine each time is that without CYA in the water, your chlorine will be depleted quickly.

Don't shock to 30 or 50ppm! The downside to taking the chlorine level too high is that you may bleach out your liner. The shock level she suggested is adequate for now. Once your CYA is raised, then your shock level will also be raised. See the Best Guess Chlorine Chart in Jan's signature above for more information about the connection between CYA levels and chlorine levels.

We'll be looking for your readings with your new kit!

Welcome to the Pool Forum!

Okay, so I think I have good news!! I tried to send my readings earlier, but my house internet was down and it was pretty hard doing it on my iPhone... I accidentally hit cancel after I was almost done.

Anyway, shocked it (15ppm) at 5:30 this morning, then around 1:00pm and again at 6pm. Each time I was getting readings of about 3ppm for FC and 5ppm for CC prior to shocking. But I tested it around 8:00pm and here are my results:

FC: 10
CC: 2
pH: 7.1
Alk: 70
CH: 90
CYA: 0

So for the first time in 4 days I got a FC reading higher than CC!! I will check again around 10:30 and bring it back to 15ppm. Hopefully I'll have good news that it held in the morning.

That brings me to the other numbers. I have been trying to bring the pH up for the last two days. I am putting 1/2 box of borax in the skimmer every 4 hours and retesting, but it seems like the pH is not budging (may have even dropped a little) I've used 2 boxes so far. Is this a result of shocking? Anything else to consider, or should I just keep doing it this way.

Also, if I do get good results in the morning then I will have to start bringing my CYA levels up. What is the best way to do that? I have Dichlor shock bags and Trichlor mini tabs for my dispenser. Can I use these, or will they take too long?

Thanks again for all your help.

Jim

So I jumped the gun. When I checked later my FC had fallen from 10 to 3 and my CC climbed from 2 to 5. So I am still shocking. The pool does look better, but I am going to keep shocking until CC is <1 and I can hold my FC levels overnight.

Hopefully you can help me with my pH question and my CYA question from my previous post.

Yes, you need to keep at it. And, once you do hold the chlorine reading overnight and have a CC reading no higher than 0.5ppm, then we usually advise one additional day of the high chlorine levels for added insurance.

Regarding pH -- keep adding the Borax. You have a large volume pool, so 2 boxes of Borax having been added isn't all that much.

I would wait on adding CYA for now. Wait until you have this issue finished. But, when it is time to add CYA, you have choices.

+ You can use the dichlor which would be a good idea in my opinion because it will chlorinate and add CYA at the same time. You'll need to monitor the CYA level periodically because it will add the CYA fast. Dichlor adds 9ppm of CYA for every 10ppm of chlorine. But what kind of dichlor do you have? Some pool chemical companies are adding unwanted stuff. Look at the ingredients and see what it says.

+ You can use the trichlor pucks but it will take much longer to have any CYA build up. It won't be as fast as with dichlor. Again, read the ingredients on your pucks. They, too, are often blended with unwanted stuff such as copper! You do NOT want copper in your pool!

+ Another choice is to just add stabilizer separately and just use bleach or liquid pool store chlorine as your chlorine source. (See what kind of price your pool store sells their liquid chlorine for and what percentage it is -- usually 10 or 12.5%. It may be a better price for you than bleach especially if they sell carboys of the stuff and that will also be fewer bleach bottles to deal with since you have a big pool.)

Okay so I will keep adding the borax. Does the liquid chlorine bring down the pH? Because now it looks like I am below 7.0. My biggest concern here is my heater. Its not on, but water is passing through it and I don't want to get metal in the water. Will it help if I bring my Alkalinity levels up with baking soda as well? That number has fluctuated between 60 and 70. 1/2 box of borax in the skimmer every 4 hours? Is that the right strategy?

As for my CYA supply, I have 1lb Power Shock bags that say 97% Sodium Dichloro-s-trianzinetrione, 3% other, with 64% available chlorine. And I have Mini-Tabs that go into my dispenser that are 99% Trichloro-s-trianzinetrione, 1% other and 99% available chlorine.

Oh and I am using the carboys (I think). 5 gallon blue jugs with 12.5% chlorine.

Thanks again for all your help

Alright, so I just realized that the 1/2 box prescription for borax was for 10,000 gallons. And I had my Pool Calculator on my iPhone set to "soda ash." Pool Calculator says I need to add 154 oz. of borax to raise it from 7.0 to 7.6. So I added a whole box (76 oz) and I plan on adding another box later tonight after testing. That should get me back on track.

Liquid chlorine does not raise pH--it in itself is alkaline, but the reaction with junk in the water is acidic, so basically you have a draw--no real measurable pH change. However, if you start using the dichlor or trichlor, keep in mind that it will drive your pH way down, so you'll need to keep an eye on it. If you're using dichlor or trichlor, bumping the alk up a little to the 110-120 range will help stabilize the pH, but if you're going to use any other form of chlorination long term, you'd be better off leaving the alk at 70.

Right now, just concentrate on keeping the pH above 7.0, and your chlorine at 12-15 ppm until whatever's causing your CC burns off (I'm betting it's ammonia demand from last year's CYA degrading--do you know what your CYA was at closing last year? Did you use a lot of stabilized chlorine last year?)

Janet

Yeah, ammonia demand sounds right. I don't know what my CYA was last year, but all we have used the last two years is dichlor shock once a week and trichlor mini-tabs all season. We moved in two years ago and I have been relying on the pool store for everything. No more!!!

Glad I found this site. I would have been further in the pool store web of chemicals. Thank you so much!!

Okay, I just wanted to give you an update.

So far I have put in 15 bottles (1.42G) of 6% household bleach and 5 carboys (5G each) of 12.5% liquid chlorine. That's 21.32G of 6% and 25G of 12.5%. By my calculations that is (21.32*.06)+(25*.125) = 4.4G of pure chlorine. Or (4.4G/27,000G)*1,000,000 = 162.96ppm for my pool.

Here are my readings as of 5:45 this morning:

FC: 3
CC: 1
pH: 7.0
Alk: 75 (test turned dark red at 7, pink at 8)

I have put 5 boxes (76oz each) of borax and it has stayed above 7.0 for most of the time. But something in the shocking process is bringing down my pH.

For the first time in 2 weeks I can see the deep end!!!

My FC levels obviously didn't hold overnight, but its the first morning test I have had where FC is over 2 and CC is less than FC. Most of my morning tests have been around FC 3 and CC 5. I have to work today, so my plan is to put another box of borax in to try to bring the pH up during the day and start shocking again in the evening (around 6-6:30). Then I will test every hour and bring FC level back up to 12-15ppm until bedtime (11:00) and test again in the morning. I will keep repeating this process throughout the week until I can hold my FC level overnight.

Thanks again for you help and support!!

You are welcome. Keep us posted how it is going.

Hang in there--it'll work, just don't give up :)

UPDATE:

Water looks amazing...crystal clear!! I am still losing FC overnight, but all of my readings for CC have been at or below 1. My last test at 10:30 last night showed FC 10.5 and CC at 1. Here are my results from 5:45 this morning.

FC: 3
CC: 0.5
pH: 7.6
Alk: 85

I do have one question. I am going to continue to shock until I can hold FC overnight, but should I start using Dichlor to raise my CYA levels?? They are at zero and I am concerned about have NO chlorine in the pool during the day. Using the Pool Calculator, I could use 5lbs of Dichlor and bring my FC into my 12-15ppm range while also introducing 11ppm of CYA. Obviously, I would watch these levels with a target of about 30ppm(??). Once I hit those levels, I could switch back to liquid chlorine if necessary. Anything wrong with this strategy??

Thanks,
Jim

You can use dichlor but just be aware that as the CYA level comes up, so does the needed shock level to kill whatever is in your pool. If you haven't already done so, please read the Best Guess Chlorine Chart in my signature. I would also suggest a CYA level of around 50 as opposed to 30. (Actually, maybe aim for 40-45ppm and that way if you overshoot a little, you'll still be ok.)

Great. Thx!

Also, forgot to add that you'll also need to watch your pH as well. Dichlor (and trichlor for that matter) are both acidic and will drive the pH down.

Hi Jim;

Here are some things that may help:

1. Link to the chlorine demand bucket test -- it will allow you to estimate how much further you have to go.

2. Links to our online pool history chart -- if you add the data, I'll turn on the graphing:

Pool History Chart
Pool History Results

3. Links to the online pool chart, allowing us quick access to your physical pool info:

Pool Chart Entry Form