Cloudy water after filter change

[JMann]

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

[aylad]

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!!

[JMann]

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

[Watermom]

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!

[JMann]

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

[JMann]

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.

[Watermom]

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.)