Tannins in Pool Water?

[nrbarnard]

Hello! I am from Illinois and recently filled my pool. Right or wrong, I knew that tannins is in the water. But how do I get rid of it? The rest of the water is in pretty good shape (Tested at the pool store), but they were unable to test for tannins. Trying to avoid expensive chemical prices...

Thanks!

[PoolDoc]

Upgraded membership; moved thread to chemistry problem section => you may need to log in and log out to gain access!

To start with, "expensive chemicals" won't help with tannins . . . if that's what it is.

But you need to be sure. Both tannins and iron (and, more rarely, manganese) can turn water brown. Maintaining high chlorine on sunny days will often remove tannis . . . but that same treatment will make iron stains WORSE.
What led you to conclude that the water has tannins? Brown water? Brown stains? Somebody said so?
What sort of water are filling with? (Municipal, well, surface)
Does that water NORMALLY contain tannins? Will this be a 1x or ongoing problem?


. . . . more info is needed . . .

[nrbarnard]

Thank you for the response, Pooldoc. The entire village supposedly has tannins. But I think it is just iron. Took a sample to the pool store to have it tested. He said that he has treated many pools from that village. Alkilinity is way high (>250). So he gave us a liquid chemical (super potent). Was told to add 32 oz twice a day for 4 days. Then bring another sample in. After running the pump for 24 hours, I checked the filter and it was orange. This is village water, not well. Rest of the tests were fairly close to acceptible ranges.

[PoolDoc]

Sounds like iron.

If you get some of the orange filter waste or goo, put it in a glass with enough water to suspend it, and add either some Vitamin C tabs (ascorbic acid) or some Iron Out. If the water clears . . . it's iron.

Likewise, if you have an orange spot you can reach, but a few Vit C tabs on it, or a Iron Out paste (in a twist of Saran wrap). Again, if it clears, it's iron.

[nrbarnard]

Did as you suggested and it cleared it right up... So with that said, should I keep doing the hydrochloric acid (33%)?

[PoolDoc]

OK. So, you've got iron?

Post full pool and test info (gallons, pool surface, filter type + test results)

And, if possible, find out WHERE the iron is coming from. One way to check is -- if your toilet fills with the same water as the pool -- is to check the toilet tank. If the interior is dark orangish-brown . . . you have iron in the fill water. (But, if you have a softener or iron removal filter on the house this won't work.)

Meanwhile, run the filter 24/7, but make sure the return eyeballs are directed so that water flow is NOT directed against a pool surface.

[nrbarnard]

Ok, finally got my numbers with me to enter them onto this... I think the Iron content is mostly removed... I did the 5 Gallon Bucket/Poly-fil project to get rid of a lot of it. And not as much is appearing in the pump filter anymore. Below are the updated numbers from two days ago. Water inside the house is taken care of by the culligan system. I am adding 1 quart of Muriatic Acid twice a day currently. Could also use some guidance on Chlorine. Currently using regular clorox bleach.

Intex 22' x 52" Round Above Ground Pool
10,000 gallons
2500 GPH Cartridge Filter

PH: 8.5
Alkalinity: >250
Hardness: 480
Total Chlorine: 3.2
Free Chlorine: .3
CYA: 2

[PoolDoc]

"2" is not a possible reading for CYA. Did you mean "20"? What kit are you using? Anyhow, with ZERO algae, your FC should be 5% of your CYA.

Are you using 31% muriatic from Lowes, etc? If not, you should be. I don't understand how you have pH/TA/CH that high without cloudiness. But if 1 quart at a time is not producing a change, go to 1/2 gallon per dose.

UNLESS . . . you are using diluted acid. If so, try 1 quart when you get full strength acid. And, READ the "Using Muriatic Acid" page linked in my signature.

[nrbarnard]

I seriously appreciate all of the information. Can we donate to your page somehow?

The printout I received from the pool store has the CYA at 2. I am using the full stength acid. So I will up it to half gallon doses.

[PoolDoc]

Thanks; you can 'subscribe', using the link in the upper right corner of my blue sig. box.

Currently, subscriptions don't get you much, so it would be a donation.

[nrbarnard]

I am now subscribed. :)

So good news and bad news... Got the Alkalinity down. I don't have the numbers in front of me, but its around 120. However... PH dropped quickly, I should have tested every day, but didn't. Its down to 6.6. First and foremost, is that safe to swim in? I read your other post about Borax. I have added 6 cups of borax (10,000 gallon pool, 1 dose) last night. I will be checking today to see how the pool adjusted.

[PoolDoc]

Intex 22' x 52" Round Above Ground Pool - 2500 GPH Cartridge Filter
10,000 gallons - PF=12

A pH of 6.6 isn't unsafe . . . but the problem is, it may not be "6.6", either. Probably, that's just as low as your kit or strip goes, so an actual "6.6" or an actual "4.6" would still READ 6.6!

Don't swim till your pH is ABOVE the lowest value your kit can detect.

Are the stains gone? What is your stabilizer level? What is your calcium level?

(Thanks for the subscription!)

[nrbarnard]

Can you help me understand where you got 12 cups? I used the link below and I came up with 6. I believe you of course, but just want to understand. 😊

http://www.poolforum.com/pf2/showthread.php/17055

[PoolDoc]

"PF=12" is more a note to me. It means that your pool is 1/12 of a million pound pool, or that 1 pound of stabilizer (or chlorine gas) will add 12 ppm of stabilizer (or chlorine).

PF (Pool Factor) offers a quick way of calculating doses:

PF x pounds added x % concentration = PPM added.

So, in the case of 1# of dichlor (55% chlorine; 50% stabilizer), the calc is:

12 x 1 x .55 = ~7 ppm added (6.6) for chlorine and 12 x 1 x .50 = 6 ppm stabilizer. (I know the percents don't add up: but chlorine percents are reported compared to chlorine gas, which is 100% chlorine gas, but when hydrolyzed is ~50% HCl and ~50% HOCl. HCl is muratic acid; HOCl is chlorine in the pool or sanitizing sense.)