Back to chemistry class...

[Donna's Poolboy]

Morning update:

FC 16
CC 0
ph 7.5

Water looks great, crystal clear. I added 2 jugs of bleach to take the water back up to 20 ppm. The ph came back up to 7.5, so it looks to me like I'm making progress, yes?

[CarlD]

Sounds like you are doing great!

The bleach in large quantities MAY be increasing your pH a bit--even though bleach has high pH the chem action lowers pH to compensate...mostly.

But the dramatic drops in FC mean you aren't out of the woods yet.

Chem_Geek's advice in a nutshell is: With no FC in the water dangerous bacterial contaminants (most seriously fecal matter) aren't killed and can multiply. Keeping the FC up is critical to keeping the water sanitary.

Pond swimming depends on the pond. First off, they are usually far, far bigger, hundreds of thousands or millions of gallons, so a contaminant is far more diluted. Secondly, a pond is an ecological system, a pool is not. The pond has natural mechanisms to deal with biological matter, such as plants and fish, plus it frequently has a constant exchange of water. Also, there is the natural filtering of the ground: Remember, a pond is where the surrounding ground is SO saturated that the water cannot be absorbed--something like 3x the water is in the ground as is in the pond, and that's a filter.

And, the bottom line is: Just how safe IS that pond to swim in?

[Donna's Poolboy]

Another big drop in FC today...
FC 13
CC 0
ph 7.5

A 7 ppm drop in 10-12 hours is pretty huge. I agree, Carl...not out of the woods yet! I just added 3 jugs to take the FC to 19 and I'll test once more tonight.

Thanks,
Bill

[CarlD]

Bill, just stay on top of it. Test at least 2x a day but 3x is better.

Otherwise, you are doing what you must do. Keep your supply of P.O.P.P. full!

(that's Pool Owner Patience and Persistence)

[mbar]

It took my pool 6 days of keeping my chlorine up to 20 by testing 3 x a day to get my chlorine to stick overnight. Even though by the 3rd day there was no combined chlorine, it was still using it overnight. Finally the last 2 nights it has stayed consistant, so I am letting the chlorine drop down today. The water went from a swamp with green stringy algae last Friday, into crystal clear beautiful water! Even my husband wanted to drain and refill when we opened last Friday, but I knew after reading this board for a couple of years that any water can be cleared with lots of Bleach and POP.

[Donna's Poolboy]

Okay...here I am about a week into my pool's voracious chlorine appetite problem. The last 2 nights, the water lost 2 ppm overnight. However, between 4:30 am and noon today, the cl dropped by 6 ppm and the pool is just now getting into full sun. A 10 or 12 ppm drop during the day hasn't been uncommon. I'll bet this thing has gobbled up 40 jugs of bleach since last week.

It's hard to tell if I'm making progress. The water is crystal clear and the ph has been stable since this weekend. I've been diligent about vacuuming, testing and adding bleach to keep the cl at 20 ppm. I've got a nylon in the skimmer, so I've only backwashed once. (Or, should I be doing it daily?)

I bet other people who've had this problem can relate to the feeling of "I MUST be doing something wrong." You start questioning everything--maybe I got a bad batch of bleach, maybe my reagents are bad, maybe my neighbors ARE right and I DON'T know what I'm doing, maybe the people in charge of the forum have stock in Chlorox... (by the way, the bleach is fresh and the reagents are all new!)

Here are my latest numbers
FC 20
CC 0
ph 7.5
cya 60
alk 160
cal 220

So this is the part where I throw my sob story and my boo-boo face onto you guys (and gals). I'm hoping that there isn't a serious problem. I'll be waiting for a sympathetic shoulder and a hankie to dry my crocodile tears. In the meantime, I'm off to WalMart. They're having a sale on liquid patience. Wha'd ya think...4 maybe 5 gallons?

Thanks,
Bill

[CarlD]

If your pool is staying so clear, you may want to just see if you can hold your FC in the 5-10 range now.

Otherwise your numbers look fine.

[mbar]

I have been having the same problem. It is two weeks now, and my pool is using extreme amounts of bleach. I thought it was getting better, then today it dropped 12ppms I think it may be all of the pollen and caterpillas falling into the water. I keep getting no cc and the water is clear, but I don't really want to drop the chlorine down low until it is holding overnight. I have been trying to keep it at 15, but may try boosting it up to 20 again for a time to see if that is what it needs. My cya is only at 30. I will keep you informed

[Donna's Poolboy]

Marie-
I was starting to wonder about the pollen. I just checked the skimmer sock that I replaced yesterday and it was PACKED with what I'm assuming is pollen skimmed off the water. Pollen is an organic material...maybe that's contributing to the chlorine loss. It dropped 1 ppm overnight, but I've lost around 12 ppm in 24 hours. However, the water is crystal clear.

I read Ben's spring start up tips:
http://www.poolforum.com/pf2/showthread.php?t=190
Although I didn't lose all my cya over the winter, I did drop from 100ppm to 60ppm. I wonder if that is contributing to the radical loss of cl.

[chem geek]

If your CYA drop was due to bacteria consuming the CYA, then that produces ammonia so that will consume chlorine very quickly (and make combined chlorine go up very fast until breakpoint and eventual breakdown mostly from sunlight).

Every 1 ppm of CYA that gets broken down to ammonia (and carbon dioxide and carbonate) requires 2.5 ppm FC to fully break it down (it's not 10x due to the fact that the CYA is a much heavier molecule so the "ppm" represents much less substance than "ppm" of chlorine).

If all of your 40 ppm CYA loss was due to consumption by bacteria, then it would take 100 ppm FC cumulatively to clear your pool. I suspect that at least some of the CYA loss may have been due to dilution from winter rains so your total chlorine consumption wont' be 100, but it would be interesting to know what it ends up being. Be sure to let us know.

Richard