Another algae question

[Watermom]

Use a little muriatic acid to lower your pH some. Add about a pint slowly in front of a return jet -- gloves, glasses, stay upwind of fumes, pour very close to the water to avoid splashing. After a few hours, retest pH and repeat til you get below 7.8.

You need to shock your pool back up to 15. Also, run the pump 24/7 to let the filter trap the dead algae. Test your cl in the evening after sundown and then again in the morning within 2 hours of sunup and see if you are losing more than 1ppm of cl overnight. If not, your algae is dead and now it is time to be patient and let the filter do its job. (Don't test your pH when the chlorine is high, however, or you'll get a false high reading.)

You might try adding a little DE to your filter. Many of us with sand filters do this to help it filter a little better. More about that here:

http://www.poolforum.com/pf2/showthread.php?t=3742

[jstkiddn]

Use a little muriatic acid to lower your pH some. Add about a pint slowly in front of a return jet -- gloves, glasses, stay upwind of fumes, pour very close to the water to avoid splashing. After a few hours, retest pH and repeat til you get below 7.8.

You need to shock your pool back up to 15. Also, run the pump 24/7 to let the filter trap the dead algae. Test your cl in the evening after sundown and then again in the morning within 2 hours of sunup and see if you are losing more than 1ppm of cl overnight. If not, your algae is dead and now it is time to be patient and let the filter do its job. (Don't test your pH when the chlorine is high, however, or you'll get a false high reading.)

Thanks! Just added the muratic acid and will retest in a bit.

I need some clarification on shocking the pool back up to 15. First off.....15 as in fifteen? Or 15 as in one point five? I bought some generic household bleach yesterday (6.x%). I had specifically asked Foxx pools several years ago if I could use bleach in vinyl pool and she said an emphatic "No!". I have a feeling that she was wrong. But before using, I just wanted to check to be sure. I can use in vinyl, right?

If so, how much bleach does one put in to raise the levels? I need someone to explain this to me like I'm six. With the salt generator, we usually don't have to shock and when we do I'll admit its usually involved hubby going out there and throwing in some shock willy-nilly. I would like to be pointed to some specifics.

Thanks again! You guys are very helpful!

[aylad]

You absolutely can use bleach in a vinyl pool!! Pool store "liquid chlorine" is 12% sodium hypochlorite. Plain, generic ultra bleach is 6% sodium hypochlorite. Same stuff, just a lower concentration. Haven't met a pool store person yet that can tell me why it's okay to put 12% bleach in a vinyl pool, but not 6%!!! My pool is IG vinyl liner, and bleach is basically the only chlorine source it ever sees, so I can tell you from experience that it's okay.

Anyway, in a 30K gallon pool, each 2.5 gallons of 6% bleach will raise your chlorine by 5 ppm. And when Watermom said 15 ppm, she meant 15, no decimal points! After you get to the initial 15 ppm, then each 1/2 gallon you add will raise your chlorine by 1 ppm, so you can use that as a guide if you find that you're losing chlorine overnight and need to maintain that shock level a little longer.

Janet

[jstkiddn]

Just wanted to update:

I've been super busy this week and really haven't done a lot of other things to the pool besides brush the walls and vacuum a couple of times. I did add DE to the filter. Let it run over 24 hours right after adding and since have run it at least 12 hours a day. After adding the DE, the difference overnight was AMAZING!! Still have some stuff that needs vacuuming but I think I've about got it licked. I have NOT added any chlorine or bleach. There were just a couple of green spots on the walls I brushed off today, but I think they were leftover from before. The water was so yucky for a while, it was hard to see where I was brushing. Wondering if I should shock again or just leave well enough alone?

I received my Taylor test kit this week and finally had time to use it today. Hopefully I did everything correctly, so here are the results:

Free Chlorine - 2.4 ppm ?? This one was kinda tricky. Used a 25 mL sample Turned pink with 2 dippers. 12 drops to colorless x .02 = 2.4 Right? On step 5 there was NO pink...so no combined chlorine? Right? Whatever THAT is. Since didn't turn pink, I didn't do steps 6 or 7. Is it supposed to have combine chlorine?
Ph - 7.6 or 7.8 (think I'm color blind when it comes to pinks. I have a hard time with this one)
Alk - 100 ppm
Hardness - 100 ppm
CYA - 40 ppm

The water is finally clearing up. I attribute most of this to adding the DE to the filter.

Thanks for reading and hopefully someone will tell me my next step.

BTW - One more question. If I do need to shock by adding bleach, do I add to skimmer or just pour into pool?

Sorry to be so dense, but I just want to make sure I do this correctly. Thanks!!!

[Watermom]

You are doing the tests correctly. But, with a CYA of 40, your chlorine level should never go lower than 3ppm. Keep it between 3-6 all the time. That may be why you still see green. I would suggest shocking the pool up to 15 and see if that takes care of the algae for good. If you can go from sundown one evening to sunup the next morning without losing more than 1ppm and you still have no CC, then you are OK and can let the cl drift down to 3-6. You can either add the bleach slowly into the skimmer or slowly in front of a return jet. All other levels look fine.

BTW -- Use the 10ml sample instead of the 25ml sample to make your reagents last longer. Having readings within 0.5ppm accuracy is plenty.

[jstkiddn]

Thanks! I added a total of 9 gallons of bleach yesterday. 5 gallons around noon-ish and had to get more at store, so put another 4 in around 4:00. Because I figured it needed to circulate a while to get an accurate reading, I didn't test until nearly 9:00 pm and (using the 10ml sample) used 20 drops to clear. So, 10ppm? Left the pumps running overnight.

Just retested again this morning at 6:30 am (19 drops to clear) and got a reading of 9.5 ppm. No CC.

The thing that puzzles me is after adding so many bottles of bleach, why was my chlorine level only 10 ppm when I tested last night? Now I'm wondering if I messed something up. Could that be right.....could it have been used up that quickly?

The water is clear!!! WHOO HOO! No stuff on walls either. Spent literaly hours vacuuming yesterday and after 'the dust settled', this morning there is but the smallest amount of sediment that settled in the corner of the deep end. I think that one more round with the vacuum and I'm home free.

I do have a couple of other questions. After adding the bleach, when is it safe to swim again? At what level is there too much chlorine? Also, I've noticed the water has a vaguely sticky feel to it. Or rather one's skin feels a bit sticky after putting in water. What could cause that?

Thanks again for all the help! I was ready to pull the proverbial plug on the pool last week.

[jstkiddn]

Also wanted to add: re: sticky water My first thought was maybe salt, but our Pool Pilot says the salt level is 3600 ppm and the HTH salt test strips pretty much agree (3680)....but not sure of the accuracy of either. It's not horrible sticky, but just as it dries, my fingers feel sticky for a bit. Then it goes away. Maybe it's been so long since the pool has been open that I forgot what the saltwater feels like? LOL Just don't know what else it could be.

[PoolDoc]

Chlorinated water is pretty much 'safe' to swim in any level that doesn't turn your swimsuit white -- it may not be 'comfortable' to swim at really high levels, but unless you spend 24 hours in the pool at, say, 200ppm, I don' think safety is going to be an issue.

There's some pretty random history behind the EPA mandated "don't swim till levels drop to 3ppm" warnings, that I can't go into here. But at the same time the EPA generated those warnings, they were allowing drinking water treatment plants to operate with NO upper limit on chlorine in drinking water! Even now, there's only a 4ppm 'warning' limit, which means basically, "OK, guys, start working on getting that chlorine level down, but no, you don't have to call your customers." It's sort of a left hand doesn't know the right hand thing.

Regarding sticky -- yeah, salt is sticky. I just converted a customer's 200,000 gallon pool to salt, and I find I tend to rinse my hands off afte working with the pool, because of that feel. But, the country club members all seem to like it, so I'm happy.

[Yeggim]

Also wanted to add: re: sticky water My first thought was maybe salt, but our Pool Pilot says the salt level is 3600 ppm and the HTH salt test strips pretty much agree (3680)....but not sure of the accuracy of either. It's not horrible sticky, but just as it dries, my fingers feel sticky for a bit. Then it goes away. Maybe it's been so long since the pool has been open that I forgot what the saltwater feels like? LOL Just don't know what else it could be.

I get that sticky feeling on my hands when I'm shocking the pool. It's like a sticky soapy feel. If I pour 6% Bleach directly on my hand, it's the exact same feeling only more pronounced. Could it be that the natural oils on the hands actually saponify into soap? Anyway, the sticky feeling disappears once my Chlorine levels come down.