Newbie w/ very GREEN pool - HELP!!!

I have a 24' above ground, vinyl, 4.5' deep pool (13,5000 - 15,000 gal.) with a sand filter. We moved last fall so this is all new to me. Trying to learn fast, because it suddenly turned very green!
Just purchased a Taylor K-2006 kit.

8-11-2010 test results: midmorning
FC 3.6 ppm
CC 0.4 ppm
CYA 100
pH 7.9
TA 170 ppm

Last evening after sweeping, dumped in 4 jugs of Chlorox (6%) = 5.68 gal. That was my best guess for shocking levels after looking at the 30 ppm super shock for algae removal table in the kit booklet. It didn't give guidelines for 6%. I also added water from the outside spigot because water was almost too low to run filter. And it rained last night.

8-12-2010 test results: morning
FC 16.2 ppm (had a little difficulty w/ this test: couldn't get water to look totally colorless. the 16.2 mark was where it looked almost clear, but as I kept adding drops it turned peach color. so I didn't get a CC reading)
CYA 90
pH 8
TA 180 ppm

Filter has been running nonstop since it turned green.
Did I put enough chlorine in last night for a super shock? From reading I think my CYA is a big problem. And I've read to empty half the pool. Honestly I really don't want to do that. Any other ways?
What's my next step?

8-203-2010 I had my water tested by a pool store. Here is their results:
FC 1.9
TC 3.3
CC 1.4
TA 167
pH 7.6
CYA 32

Did add some dry acid and then the second time several days later. Dry acid may have been old product, was here when we moved. Tuesday morning (I think) I dumped in a 1.42 gallon jug of Chlorox. Wish I had posted on here sooner and got to working on my problems faster. Is my CYA testing way out of whack or can it jump like that from not doing anything? Do you need more history from earlier this year?

Hello gettinthesplash,
Welcome to the forum!!

I'm assuming that you've been using either trichlor pucks or dichlor shock to chlorinate your pool, which is why your CYA level is so high. Most people don't realize that the higher your stabilizer (CYA) gets, the higher levels of chlorine you have to keep in the pool to compensate for them. With a CYA of 100, you need to be keeping your chlorine levels at an absolute MINIMUM of 8 ppm, your target range is 8-15 ppm. When you shock, you need to get it up to 25 ppm. In your pool, the 5.5 gallons of bleach should have gotten you up to the 25 ppm, but you have to MAINTAIN that 25 ppm in order to clear the pool up. You do this by testing and adding whatever amount you need to get back up to the 25 ppm mark, as many times a day as you can. Each quart of bleach should raise your chlorine by 1 ppm, so you can use that as a guide when figuring how much to add to get it back up to the 25 ppm level. It is consistently holding the pool at shock level that will kill and clear the algae. If you shock it and let the chlorine just come down again, you're wasting your time and bleach, because it takes sustained shock levels to kill the green. Also the pump needs to be running 24/7 with an eye on your pressure gauge, cleaning the filter as necessary, and brushing the pool at least once daily. You need to hold the shock level until 1)the pool turns blue and starts to clear, 2) you have zero CC, AND 3) you don't lose any chlorine when testing at night and again in the morning before the sun hits the pool. At that point you can let it drift back down to the 8-15 range, but never below 8--at least not until you're ready to drain and refill part of your water to make the CYA more manageable. (And BTW, I would trust your CYA testing over the pool store's testing--the only way for it to drop from 100 to 32 is with major replacement of water). I definitely wouldn't use anymore trichlor or dichlor in this pool, because it's just going to drive your stabilizer higher--you'd do better to switch to just plain, unscented, generic bleach.

Just curious, why add the dry acid? Your pH is okay where it is....

Janet

Also, just to be sure you are at 100ppm on CYA, try to dilute your pool water 50/50 with bottled water and repeat the test. There is a good chance your CYA is above 100 ppm, which would make shocking very difficult.

I put in the dry acid because my TA was high. And for clarification, the pool store test was done a week or so before I tested. The end of July we were away for 4 days. Water looked good except for being cloudy. We had a solar cover on and put 5 pucks (trichloro-s-triazinetrione) in the dispenser. Husband said it looked fine right after we got back, but in a day or two it was definitely green. Then I took it to be tested at the store. Yes, we've been using trichloro granules.

I'm sorry for the typo. The pool store test date was 8-03-2010

Your TA is a little bit high, but in a vinyl pool, is actually okay where it is, for now....the green water should be much higher on the priority list! :)

The CYA is a very subjective test, and because it relies on turbidity for results, an algae outbreak can definitely affect the reading. So can reading the test without letting the sample sit for a few minutes after mixing with the reagent. So can reading the test in dimmer lighting than the previous time. See what I mean? So....the best you can do right now is base your shocking on the higher CYA level, and then test for CYA again after you get the pool cleared up. The key is going to be getting that chlorine up to 25 and keeping it at that level until the algae dies off. You'll know you're getting there when your water goes to blue-cloudy, which will be the dead algae that needs to be filtered out.

As I said in my above post, I definitely wouldn't use any more stabilized chlorine in this pool. You didn't list a hardness reading--too little hardness in a vinyl pool is irrelevant, but if you really want to continue to used powdered chlorine, then you may be able to switch to cal-hypo granules for a little while, depending on your current CH level. YOu can't let it get too high, though, especially with TA and pH on the higher side because it can contribute to cloudy water. I would just use bleach, personally--it gets the chlorine in the pool, and doesn't add anything else that you have to watch out for!

Janet

The

Thanks Janet for all your advice. I plan to stick to the bleach and get rid of the other chlorine. Gonna go do some more testing and probably add some more bleach and see if I can keep the level up where it needs to be.

Just tested again:

FC 16.0
CC 1.0

Added 9 qt. of bleach. Gonna do all I can to get rid of that ugly green!!

To speed things up you may want to consider a partial drain and fill to lower your CYA level. Battling algae with CYA at 90-100 will be very difficult. It can be done, but you are going to need a ton of bleach/liquid clorine to maintain that high of an FC

Should I keep my solar cover on to help keep the chlorine in? Or will the high levels of chlorine ruin my cover? And will my high levels of chlorine affect my cya test results?

Leave the cover off. Fumes from shock levels of chlorine can damage the cover. Your cya test will not be affected by the high cl levels.

How soon should we expect results (green clearing up)? couple days? a week or more?

Here are my results from yesterday 8-13
8:30 am
FC 27.5
CC 1.5
added 1 gal chlorine

11:00
FC 30.5
CC 1

2:30 pm
FC 25
CC 1
added 1 gal chlorine

5:00
FC 26.5
CC 1
added 1 gal chlorine

8:30
FC 28.5
CC 1
added 1 gal chlorine to make sure it didn't dip below 25 overnight.

8-14
9:30 am
FC 26.5
CC 1

Thanks so much all your help. So glad I found this forum!

If you maintain the shock level as it seems you are, you should start to see improvement within a couple of days. Run the pump 24/7 and watch your filter pressure. When it rises 8-10psi over your clean filter pressure, backwash.

3 days now with my FC at 25 ppm or higher and no significant change. The green may have paled. CYA still at 100. A little more patience and persistence? or is water change a must? If I get a chance I'll post pics tomorrow. I haven't done a backwash yet. The pressure only went up about 5, but thinking maybe it would be good to go ahead and do a backwash. Have swept/broomed the pool everyday. Yesterday just left the "lil shark" work, maybe that's not as good? It has been raining off and on too. Is that setting me back?

If it was my pool, I'd do a partial drain and refill and get the cya down. Who knows how high it really is since no cya test can distinguish higher than 100. It may take a couple of partial drains / refills which will be a pain but it will be SO much easier to maintain a lower cya pool.

Is your water green and cloudy, or is it green and clear?

Janet

Janet,
It's green and cloudy

As I stated a few days ago, trying to shock your pool with CYA at 100 is very difficult. You can try to keep at it by raising your FC level further to let's say 35ppm and holding it there or I would strongly encourage a 50% drain and fill to get the CYA down.

I agree with dmanb2b, your CYA may be well above 100, can you try diluting your pool water 1 to 1 with distilled (maybe even tap) and test the dilute sample for CYA, if it's still 100, dilute 2 to 1 etc. until you get a reading within the range of the test. The accuracy of this testing will be lower but you'll have a target for the partial drain / refill you'll need. There are some postings on this forum that describe using a plastic membrane to fill while draining without risking the integrity of your pool or wasting fill water.

It's starting to clear up! Can faintly see the bottom and it's changing to blue.

Good work!! Keep that chlorine up above your shock level, keep the filter running, and clean/backwash it as your pressure indicates. Sometimes it takes awhile, that's why one of the most important ingredients is POPP (Pool owner patience and persistence)!

Hang in there...

Janet

It's definitely blue now!! Am I right that I need to keep it at shock level until the ppm doesn't drop over night? not even 1 ppm? and CC at 0? anything else? To others dealing with algae and high CYA, definitely replace water if you don't have lots of patience and want to go swimming ASAP. According to my testing, my CYA has dropped to 60. The only "replacement" I did was backwashing and adding water to keep pool full, plus rain. Lately we've been keeping the FC @ 30 - 35 ppm. Even with diluting I could never get my CYA to test more than 100, but it sure seems like it could have been. I've been really busy and away some days so didn't always keep real close tabs on my FC levels and it dipped some. I'm sure that attributed to how long it's taking to clear it up. Feels pretty good to see progress!! Thanks everybody for your help! I really appreciate this forum.

Glad to hear you're getting some results!! You're right--maintain your shock level until the CC is zero, the water is clear, and you're not losing more than 1 ppm of chlorine when testing at sundown and in the morning before the sun hits the pool. When you reach that stage, and let the chlorine drift down, remember that with a CYA of 60 you're still going to have to maintain a minimum chlorine level of 5-10. I would try to keep it around 7-8 just to be on the safe side and give yourself a little wiggle room in case of a rainy day or forgotten dose of chlorine.

Good job! :cool:

Janet

My pool is clear!!!! What a beautiful sight!!! Now I can see my lil' shark at work. Need to check tonight/tomorrow morning to see if my FC is holding. CC is at 0. Problem is will it be warm enough to go swimming once its ready? Oh well, at least it's CLEAN and I know alot better what I'm doing and next year will be different.

I'm so happy for you! Way to go!

Quote:

---

Originally Posted by gettinthesplash

Problem is will it be warm enough to go swimming once its ready?

---

It would be if you lived down here--my water temp has finally hit a low 88 degrees!! :)

Good job on clearing up your pool. It'll be so easy for you next year!! :cool:
Janet

After all that work clearing the pool, ya gotta at least jump in for a few minutes! :rolleyes:

It got really warm again and I want to go for a swim. My problem, I haven't yet gotten it to not drop more than 1 ppm overnight. Every day it accumulates brown dirt on the bottom that is very easy to sweep up. Is that dead algae it's still killing or dirt blowing in? What's the damage of just letting the chlorine drop so maybe we can get in another time before we close it up? Monday night it only dropped 2 ppm, last night 3 ppm. And I'm occasionally reading a trace of CC. I love to stand beside my pool and enjoy the gorgeous sight of crystal clear, beautiful water!!!! Can't get enough of it. Thanks again everybody!! So glad I found you!

If you are measuring Free Chlorine (FC) then the pool is sanitary though your overnight chlorine drop indicates the chlorine is still killing off or oxidizing algae or organics. Though it's not normally recommended, it is still safe to use the pool while shocking because at the level you are shocking with CYA in the water, the amount of active chlorine (hypochlorous acid) is roughly equivalent to a pool with around 0.6-1.2 ppm FC and no CYA which is less than most commercial/public indoor pools that usually do not use CYA.

So the higher chlorine levels will oxidize your swimsuits, skin and hair faster, but not worse than some indoor pools. You want to avoid drinking lots of pool water as it is the FC level that matters in that case, but that's not something you would normally do anyway. My wife experiences this difference every year when she swims in an indoor community center pool over the winter where her swimsuits degrade (elasticity gets shot) after just one winter season of use and her skin is flakier and hair frizzier. During the summer in our own outdoor pool with CYA, none of these problems occur and the same types of suits last for years with no sign of wear. The difference is that the active chlorine level in the indoor pool with 1-2 ppm FC and no CYA is around 10-20 times higher than in our outdoor pool with an FC that is roughly 10% of the CYA level on average.

Richard