Newbie w/ very GREEN pool - HELP!!!

[aylad]

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

[dmanb2b]

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.

[gettinthesplash]

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

[gettinthesplash]

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.

[aylad]

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

[gettinthesplash]

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.

[gettinthesplash]

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!!

[dmanb2b]

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

[gettinthesplash]

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?

[Watermom]

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.