Stinky Water - My Pool Smells Like Poop

[AngelaGarciaG]

Help! My water is clear as can be but very stinky - smells like dog pooh.

I have an inground vinyl pool. 18x36 approx 27000gallons. We have a salt generator.

chemicals are
PH-7.4
Chlorine - 6.0ppm
Alkalinity - 140
cya 80

water sparkles but smells horrible. Have upped chlorine - used floculant, vacuumed to waste, vacuumed again.

If you put your hands in the pool they come out smelling horrible.
If our just bathed dog jumps in he comes out smelling like he was rolling in dog poop.

Not sure what to try next. Please help.

[kelemvor]

I would start with getting a K-2006 or similar that will show FC+CC both. I don't know what causes that sort of smell in a pool specifically, but I'd begin shocking it. At 80CYA you need to bring FC up to 20ppm and keep it there until you lose less than 1ppm FC from sundown to sunup (with the generator OFF). Don't use your salt generator to do the shock, use regular chlorox 6% plain (unscented) bleach or some liquid chlorine from a pool store if it's cheap enough. I wouldn't use dichlor or trichlor since you already have a CYA of 80.

[Watermom]

And, it does not have to be Clorox brand. Generic bleach is fine. In fact, most of us use Walmart's generic. Just make sure you get the plain, unscented stuff.

[PoolDoc]

Hi Angela;

I spend the last hour researching this question -- you will not have made my family happy: I *already* know far more about poop than they every would have cared to know, and I tend to talk about what I know!

I don't know if will make you feel better or worse, but this problem has been occasionally reported before. Unfortunately, the discussions that followed the question were pretty unhelpful and uninformed. So, I changed the title on the thread, so other people will be able to find it, when THEY encounter the problem.

However, almost everything I learned leads me only to more questions, rather than an immediate answer. So, I need to ask you a long list of specific questions. If you would, answer them by number, in your reply, so we don't loose track.

For the purpose of the questions below, the period of interest is from 2 weeks BEFORE you first noticed the odor, till now.

1. When did you first notice the odor?
2. Does everyone in your family describe the odor the same, way, or is it perceived differently by different family members?
3. Please list EVERY, SINGLE chemical, pool additive, cleaner, etc used in your pool during from 2 weeks before you first noticed the odor, till now.
4. Precisely how are you testing your pool water? (test kit make / model)
5. How persistent is the odor on your dog? (How long does he stink, after he's in the pool)
6. How persistent is the odor on people?
7. What kind of filter do you have?
8. Is the media in it STANDARD (sand, DE, polyester cartridge) or modified (zeolite, cellulose, treated cartridge)?
9. Do you have a pool cover? Has it been on the pool during this period? When, and how long?
10. Have you had algae during the period?
11. Do you have any stagnant areas in your pool (unused spa, pool fill line, unused vacuum or cleaner line, or anything of the kind.)

Thanks. I'll try to respond as quickly as possible, once I have your information. I'm also going to contact Chem_Geek (he tracks pretty much every pool forum in existence) and see if he's seen this before.

[AngelaGarciaG]

Hi all and thanks for the responses. See my answers next to the original questions.


When did you first notice the odor? Well when we opened the pool it smelled horribly of sulfur or rotten eggs. It went from rotten eggs to dog pooh. We use a wholesale pool place who has reasonable liquid chlorine prices so we began shocking with 15% chlorine liquid and brooming the bottom that we could not see toward the drain. We added probably added 20 gallons.

Does everyone in your family describe the odor the same, way, or is it perceived differently by different family members? yes for the most part my son says it smells like dog poop with a sourness to it.

Please list EVERY, SINGLE chemical, pool additive, cleaner, etc used in your pool during from 2 weeks before you first noticed the odor, till now. The 15% chlorine (have probably added about 30 total gallons since opening), cya concentrated powder(lynde poweder chlorine stabilizer #4), baking soda, borax, pink algaecide (can't remember exact name and can't find ticket), salt (200 lbs since opening), floculant, calcium harness (can't remember name and added 2lbs).

Precisely how are you testing your pool water? (test kit make / model) Taylor K-2006 (on your recommendation we bought last year and love it!)

How persistent is the odor on your dog? (How long does he stink, after he's in the pool) Very persistent if he just walks by you it is strong and lasts for hours or until you bath him.

How persistent is the odor on people? Very - my husband had to jump in to get something from deep end yesterday and he reeked so bad I made him immediately shower!

What kind of filter do you have?Sand Filter I believe it is a Hayward model do you need more specifics?

Is the media in it STANDARD (sand, DE, polyester cartridge) or modified (zeolite, cellulose, treated cartridge)? I believe it is standard it is silica but done remember the grain -size that the pool place put in about 3 years ago.

Do you have a pool cover? We have a mesh winter cover and this year we put a solid cover hoping to keep water and muck out on top of that but it has been off since we opened. We do have a solar cover as well but haven't put it on yet. Has it been on the pool during this period? When, and how long?

Have you had algae during the period? After first opening it did turn turquoise day two or three but that cleared in about a day.

Do you have any stagnant areas in your pool (unused spa, pool fill line, unused vacuum or cleaner line, or anything of the kind.) No only thing I can think of would be space behind the light below the water line. But pool has been filtering since we opened it except for the 24 hours after adding floculant last weekend. Hoping that would help with stink.

There was mention about shocking in the response above the chlorine yesterday was at 6.7 this was free chlorine, the combined chlorine is .2ppm. Should we really move to getting this to be 20ppm? We have a vinyl liner (new last year) so I am hesitant when told to take the chlorine that high...but will do it to get rid of pooh smell if needed but we did have the chlorine up to 16ppm about 2 weeks ago...so I guess i have done it before.

Thanks for all the help it is SO Appreciated!!!

[AnnaK]

Sounds like hydrogen sulfide. Are you filling directly from a well?

[waterbear]

Sounds like hydrogen sulfide. Are you filling directly from a well?

My thoughts exactly! It can also be coming from the sand filter. bacteria can grow under the right conditions (anerobic) in the sand that produce hydrogen sulfide gas. It's actually a pretty common problem with aquarium sand filters under anerobic conditions and can kill of an entire tank or pond when it happens. If you open the filter and the sand looks black in some areas (and has a strong sewer smell) then you have found the cause. IF it is hydrogen sulfide than chlorine is the answer but with a CYA of 80 ppm you are going to have to bring it up to a minimum of 20 ppm FC and possibly higher. I would also stick a garden hose in the open filter, turn it on and let the water overflow while CAREFULLY stirring the sand and breaking up any clumps with a broomstick or something similar. Be very careful NOT to damage the laterals on the bottom of the fllter. Once the overflowing water is clean you might want to dump a gallon of bleach directly into the filter sterilize the sand.

[PoolDoc]

Very interesting, Waterbear.

I've seen black sand like that, but not had any problems after initial clean up, but then I had low CYA on those pools. After the OP does what you say, using trichlor tabs in the skimmer could help continue to clean up any remaining pockets.

[AnnaK]

Another possibility might be ground water seeping in through the bottom drain. If the ground water runs through a sulfur vein it certainly would carry a bad smell. Bleach and more bleach.

[PoolDoc]

Possible, I suppose, but only if the main drain line is cracked. Normally if that's the case, you'll have a pretty serious leak when the ground is dry.