Algae Problem with Cloudy Water

[aylad]

Hi bmlocal,

First off, you should probably go ahead and turn the SWCG off until you get the water cleared up. The SWCG is not capable of producing the amount of chlorine you need in a short enough time, and you're just wearing out the cell by trying.You'll need to manually chlorinate the water. Do you know what percentage of chorine is in the chlorine jugs you're buying? If it's 12%, then each 1/2 gallon you add should raise your FC by 2.5 ppm, so you can use that as a guide to know how much to add, once we know your CYA level. If you see brown/green algae in the pool, then you're going to have to kill it off to eliminate your chlorine demand. For now, until you know your CYA level, I would add 2 gallons of the chlorine nightlyto at least keep the problem from getting any worse until we can determine your true shock level.

Second, you are going to have to get a good kit in order to clear this up. Strips simply aren't reliable enough to help. You are going to need a kit that can accurately measure free and combined chlorine--the Taylor kit will help this project immensely.

Third, you're going to need an accurate CYA level before you even can begin to know how high your 'shock" level is. You report a CYA of 30-50 on one day, and then 100+ the next. That's not nearly close enough to work with. If your local WalMart sells the hth 6-way drop kit, it has a CYA test and enough reagents for 2-3 tests in it. You can get that and at least test for CYA until your Taylor kit gets here, so we know how much chlorine you need to be adding.

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[bmlocal175]

Alright Just got back from Walmart with 12 jugs of the 6% Great Value Bleach at $2.98 ea. and the 6 way HTH kit. Is this a good price?

It seems a little cheaper than the 5 gallons from the pool store but not sure if there's was 6 or 12%. I'm holding off doing anything until someone on here tells me to because I'm sick of spending money.

Anyways did some tests:

TC: The kit goes to 5 but it was darker than that by a little meaning 6
pH: The kit goes to 8.2 but the color seemed darker by a little meaning 8.3-8.5
CYA: wife said about 46

Turned the purifier off on the salt system and now I'm just filtering. Should I brush, vacuum, to filter or to waste? I'm below half of the skimmer now so if I vacuum to waste I will probably need to add water to keep pump running.

Waiting for some help. Thanks for the help so far.

[CarlD]

You WILL want to keep your pool at shock level for your CYA, but if CYA is 30, that would be 15, and if CYA is 100, that would be 25, and with a vinyl pool, if you don't want to fade it, that's important. (My liner is old so I don't give hoot if it fades).
No point in wearing out your SWG trying to clear your pool, but a constant level of chlorine at shock level is necessary.

Carl

[bmlocal175]

Just called my local pool store and they said the 5 gallons was the 12.5% liquid chlorine. So that seems like a pretty good deal I'm guessing for 12.99.

[bmlocal175]

Just tried a strip after vacuuming and swimming a little to see what the FC reading was. It shows around 4.

So hopefully you guys have all the info you need to let me know how much of the 18 gallons of 6% I need to dump in. Not sure how I would monitor it for I have nothing that goes to around 15ppm. The test strips do show up to 10 so maybe a darker color than that.

[bmlocal175]

Found the bleach calculator.. Typed in all of the info and it told me I need to add 16.7L of bleach to raise my ppm by 11 from 4 to reach 15. My pool is around 24,000 gallons which is about 90,850L. So that would be 3 of the jugs I got from Walmart. This thread might have some comments before this gets posted so I'm waiting until later tonight to do this so I can see what you guys think. The water does look a lot better from the 5 galllons of 12% yesterday but still cloudy. Maybe it just needs a little more time but I still would like to shock it to make sure.

[PoolDoc]

"Mountain Lake" is not a geometric shape, or at least not one I've ever heard of -- but if your pool is more or less a rectangle, your volume is more likely to be MORE than 30K gallons, than it is less than 30K. With algae, too much chlorine is much better than too little.

So . . . I'll assume a PF of 3.5 (~35,000 gallons) rather than 5 (24,000 gallons). With a PF of 3.5, a gallon of bleach will increase your FC by 0.5 lbs Cl2 equiv/gal 6% bleach x 3.5 or 1.75. So you need evening doses of 8 gallons of 6% bleach.

You can test with an cheap OTO kit -- you can skip the evening dose, IF your OTO reading in the EVENING is DARK yellow with an orange tint. Otherwise, 8 gallons of 6% bleach EVERY evening till there's no trace of algae left. After the 2nd dose, BRUSH the pool carefully.

BUT . . . if you find that your chlorine has NOT dropped after a full day of sun, THEN we know your CYA is very high. And in that case you need to NOT skip, but go ahead and take your chlorine level into the 30 - 40 ppm range (orange with an OTO kit), and keep it there, until you get your K2006.

By the way, once your chlroine goes above 10, your phenol red pH test results won't be reliable, so if your pH needs major adjustment fix it now. But, if it's between 7.0 and 8.0, you can worry about that, later.

[bmlocal175]

Here is my pool. The men who set up the salt system have 24,000 listed in the menu so I went by that.

[bmlocal175]

Alright I will wait until evening to check chlorine again. I have the HTH 6 from walmart so that is TC . Your saying if it shows higher than what the kit can show I'm good through the night? Should I leave the filter running all night with the salt system running? I have the purifier running now at about 60% on level 2 just to maintain really what I have. The water does look better but I did have to vacuum up what looked like brown stuff scattered all over the floor of the pool this afternoon.

[aylad]

The brown stuff on the pool bottom is probably dead algae, which indicates that you're making progress. Keep your filter running but turn the SWCG off so you're not wearing it out. Use the bleach/liquid chlorine to keep your chlorine up, and follow Pooldoc's directions...
"You can test with an cheap OTO kit -- you can skip the evening dose, IF your OTO reading in the EVENING is DARK yellow with an orange tint. Otherwise, 8 gallons of 6% bleach EVERY evening till there's no trace of algae left. After the 2nd dose, BRUSH the pool carefully.".

That's a beautiful pool!