Algae - need a primer!

[KurtV]

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Do the shock granules also add more CYA to the water?
If it's di-chlor, yes. If it's calciun hypochlorite, no.

I have the in-line feeder also and the dial up to about 4. I realize that most of y'all do not ue the pucks and maybe after this is fixed, I will have the confidence to go with just the BBB method.
Overuse of pucks is what got you here. Why would you be confident in the very thing that caused the problem?

Is there NO way to lower CYA other than draining the pool? If I don't add any more tri-chlor, will the level eventually drop on its own, what with rain, adding non-chlorinated water, etc.?
It will go down on its own through splashout but that will take a long, long time. The good news is that you can live with the high CYA. One you get rid of the algae you'll just need to keep your free chlorine between 8 and 15 ppm.

Thanks a lot for your help!

Good luck.

[heymom1]

OK, I understand. Good news - the algae is not visible this morning. I haven't run a test yet, but all I see is some residue at the bottom of the pool. The Polaris hasn't run yet.

When the pool was first filled, and we got the "pool school" lesson, I did wonder about the weakness of the system that included an element that only increased and could not be removed except by pool drainage. That seemed a little ridiculous to me. But we've had very minor problems with the system as is - the ph got out of whack a couple of times with rain, or we'd run out of chlorine in the feeder but catch it before anything happened.

Even this time, I could have caught it earlier had I noticed what dh was saying...He's been saying something about stains for a week now but I just blew it off. And dear son hasn't been testing like he should, even though we have a nice 6-way kit. I will order Ben's kit when it's available again!

So what DO you do if you go out of town, and you aren't there to add bleach?

[KurtV]

1. You can run the chlorine up to shock level and hope for the best.

2. You can use tri-chlor or di-chlor in a chlorinator.

3. You can get a friend to stop by every other day and add a bottle or two of bleach.

I prefer to manage my CYA so that I can use option 2. That is, have the CYA below 40 ppm when I go on vacation so that use of tri-chlor doesn't take it too high while I'm gone. I'm not always that good so I then resort to option 3. College-aged kids of friends and neighbors work well for this if you don't have family nearby to help. They're always looking to pick up a couple of bucks and some of them are responsible enough to follow simple instructions.

[heymom1]

Kurt, I will probably have to go with option 1 this time. We have no nearby teenagers or college students - only friendly with the neighbors, not friends. My FIL can come by and check on the pool but he can't come every night to add bleach. The CYA is high, around 90, but doesn't that just mean that the chlorine will stay around too?

The kids were in the pool just now, and the CL is probably around 8-10, according to the scale on my little test kit. It's a darker shade of yellow than 6, but not orange or anything.

Ph is about 7.3
No hardness
Alkalinity 100 ppm

Thanks again for the help. You guys are wonderful. I can post a photo now that we have a digital camera.

[KurtV]

If the algae is gone by then and you're just going to be gone a week, you could just leave your pool at shock level (25 ppm) and then have your father-in-law come over on the third or fourth day and add three or four 4 gallons of bleach. Three gallons will increase your chlorine by about 6 ppm and four gallons will increase it by about 8 ppm. Even if the pool uses 3 ppm per day, you'll return to a pool with at least 10 or 12 ppm which is adequate for your level of CYA.

[heymom1]

Kurt, do you know anything about ozonators? I noticed mine isn't working - the UV light isn't on, and it's too coincidental that it would go out and now we get algae for the first time. I'm sure that the chlorine level was the main problem, but that ozonator does help. I don't think pool stores carry the UV lights so I guess I have to send for one from the company.

I think you said it was still safe to swim in a pool with a 25 ppm cl level?

[KurtV]

Kurt, do you know anything about ozonators? I noticed mine isn't working - the UV light isn't on, and it's too coincidental that it would go out and now we get algae for the first time. I'm sure that the chlorine level was the main problem, but that ozonator does help. I don't think pool stores carry the UV lights so I guess I have to send for one from the company.

I don't know anything about them except that the ones that are usually sold to homeowners are generally not very effective. And I know you don't need it. If it were me, I wouldn't bother replacing the lamp.

I think you said it was still safe to swim in a pool with a 25 ppm cl level?
No, your shock level is 25 ppm. Acording to the Best Guess Chart your minimum free chlorine level is 8 ppm and the maximum is 15 ppm. You should only swim when the free chlorine level is between those two numbers.

Is your water clearing?