Newbie/1st post: Black cloudy water & leaving out of town in 2 days.... Help!

Greetings! Poked around internet & found you. Have read a few threads and now need specific help. I've gathered that I have the wrong pool test kit, and will rectify, but for now, need your help please.

Pool: Gunite 2600 gal. (25 yrs old) with blackish gray sides and bottom when we inherited it 10 years ago. Thought this was just the color from "weathering" after so many years on planet earth. Have had minimal problems with this pool. Have a Hayward DE 3620 filter (installed 2010), a Polaris CareTaker (also 2010).

However, yesterday afternoon wandered out to look at pool and there was this green glowing band hanging around the walls at the deep end. Hubby usually does the pool stuff, but is not home, so I did what any good wife would do, and dumped in ~5-6 cups of Optimum Chlor granules (Aqua-Chem) and grabbed our trusty nylon bristle pool brush and started my aerobic work out! Noticed a lot of black powdery cloudy stuff started coming of the walls, but the green disappeared and the black cloudy color of the water kept getting darker. It was getting late, so I added a few more inches of water and called it a night.

This am, couldn't see the bottom of the pool, so backwashed, put in fresh DE media, and scrubbed the walls again for the second time in less than 24 hours.... much more black cloudy dusty stuff rolled of the walls & much sorer arms. Now, 6 hours later, went back outside thinking things should start looking good.... but no sign of the pool bottom in sight! So, (don't cringe).... tested the water with my PoolMaster 5 way test kit... (sorry, now realize this is bad)... will order the Taylor K-2006 asap. However, here's all I can tell you right now: Instant Cl - 5++, Residual Cl - 5++, TA - 70ppm, pH - 7.2. Obviously, I have know idea how high the chlorine is since this kit only goes to 5. Oh, did I mention, I just now also grabbed the pool brush to see if the walls were clean and a cloud of black dust rolled off with the first swipe!! Yicks!!

So, ?'s: 1) Do I have to keep brushing (each time it is an hour of scrubbing and sorer arms)? 2) If I need to just add more chlorine.... how much, and should I use more Optimum.... or I read some posts of people using straight chlorine bleach (which I have a lot of)... at 6% Chlorox brand. HELP please!! Thanks for reading.

Hi! It sounds like you may have years of black algae. Or it's a huge accumulation of sunscreen oils.
If you dilute your pool water 1:1 with distilled water, you can double your chlorine reading ("5" really is 10). 2distilled to 1pool and you can triple your reading.

But without a stabilizer measure it is hard to know how much chlorine you need.

Is that 2,600 or 26,000 gallons? 2,600 seems small to me for an inground pool. This is a key value when it comes to figuring out how much bleach (or acid or baking soda or whatever) to add.

As CarlD said, you aren't going to know how much chlorine to put in there until you know your CYA (Cyanuric Acid aka Stabilizer) level To know that, you need a test kit that tests CYA. Until you get the K-2006 kit in you can get by with an "HTH 6 way test kit" from walmart. They're listed at $22 on the website, but the idea is to get it from the store so you can get it today. Here's a link so you'll know what to look for: http://www.walmart.com/ip/HTH-6-Way-Test-Kit/17043668 There is also an "6 way test STRIP" kit that you do NOT want. You want the kit that uses liquid drops.

Cleaning up a problem like that (assuming it's not black paint chalking off?) takes some time. Time and consistency. If you're going out of town you can't be consistent right now. Honestly I wouldn't waste money starting cleanup until I got back...Unless your town is like mine where it is illegal to have a green pool.

Here's some reading material: http://www.poolsolutions.com/gd/the-...pool-care.html <- read first

Here's some more: http://www.poolsolutions.com/gd/best...ine-chart.html <- read second.

Once you get a test kit that measures CYA, post that number and someone here can help you get started.

Thanks to kelemvor & CarlD for your input ... And yes, it's 26,000 gallons. Spent the last 36 hours scrubbing walls four full times (and starting to educate myself on pool chemistry when my arms needed breaks!). Added about 4 qts trichlor granules plus four gal 6% Chlorox bleach. A bit of a shot-gun approach i'll admit, but the Cl (both free and combined) were staying elevated using the stabilized form and wanted to get things rolling at least in the right direction by adding a non-stabilized super chlorination cheaply with Clorox bleach. My TA and pH were holding and figured the disinfectant properties of Chlorox where maximized due to low pH (around 7.1). Ran the filter constantly since my first post yesterday and by about 8pm tonite the water color is blueing up .... Having low 70's and cloud cover helped. So have just shut down the pool and Kelemvor is right.. The rest will I have to wait till we get back in town.

Anyhow, just can't tell you how ! freaked out ! I was (and am) realizing yesterday that we've been swimming in a black algae coated pool for several years, even though the walls have felt rather rough like sandpaper (read.... NOT slimy until I saw the green slime) all along, so just assumed the usual blackish/grey colored walls were the color of the gunite. Wondering when hubby and I start growing a third arm or something! However, the two I have at the moment need a major rest..... So perhaps a third and fourth will be helpful.... Think there'll be a lot more wall scrubbing in the next week or two :) Will get the CYA test drops or Taylor kit before proceeding..... To be continued.

P.S any docs out there feel free to weigh in on the health risks?!?!

Algae doesn't really hurt you, it's just considered unsightly by most. Algae occurs naturally in lakes, rivers, and oceans. Lack of proper sanitation can leave your pool full of germs and bacteria that CAN hurt you though. However, what kills the bacteria also kills the algae as far as I know so....

As far as those trichlor granules, I would stop using them immediately. They add CYA to your water and I'm going to hazard a guess that your CYA is high if that's all you've been using for years. Overly high CYA renders chlorine ineffective.

http://poolsolutions.com/gd/avoiding...ing-pools.html

To continue: "Stabilized Chlorine" makes you think it's "different" kind of chlorine from bleach. It's not. Chlorine is chlorine. But as Tri-chlor dissolves, it releases Cyanuric/Isocyanuric Acid (aka, CYA), which is chlorine stabilizer. You can get the same effect by adding bleach and adding granulated stabilizer/CYA. Tri-chlor is also very acidic and can lower your pH quickly.

While algae IS harmless (as kelemvor points out), it is the canary in the coal mine that your chlorine level is too low to kill the harmful stuff. Further, your chlorine is spent killing the algae and isn't available for the bad stuff. So killing algae is necessary to keep enough chlorine to kill bacteria and viruses.