Cannot defeat this ALGAE!

Algae problems in swimming pool water.
Green (cloudy) water or slimy pool walls.
Black algae. Mustard algae. Pink or white pool mold.
woslambert
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Cannot defeat this ALGAE!

Postby woslambert » Mon 13 Jul, 2009 01:13

Hi
This is my second year owning a pool and I am having the hardest time getting it clear this year. WE didn't cover it last winter so yes it was yucky and full of leaves but I purchased a polaris 165 and let it run until it didn't bring up anymore debris in the bag (I even brushed the pool to help it out). We shocked it with 20 gal of 2.25% chlorine bleach plus 2 bags of diclor shock then four hours later 4 more bags of dichlor shock. Next morning still just as green as before we put that in. This was July 10th. Got up next morning and FC was down to zero again! Last time I took sample to pool store was July 3rd adn my cya was 30ppm. I don't have a test kit that will test CYA as of right now. We are trying to sell our home and spend the least amount possible right now. Our pH is at 7.1-7.2. We read the article "Turn your green pond into a sparkling oasis" and it advises to keep pool at shock level and make sure FC holds at that level for several hours to kill off algae. We have been doing that since Friday night and so far its holding steady at 13ppm. Can someone please advise on what to do? A few weeks ago we shocked it and got it to the milky light blue but could never get the water to clear up. Pool store told us we needed clarifier, bromine, unstabilized shock, de filter media and algaecide. All that didn't work either.


Swimming Pool Helper

Cannot defeat this ALGAE!

Postby Swimming Pool Helper » Mon 13 Jul, 2009 16:20

Go on this website and watch the video for "pool school". You can download or watch. Good pool help.
http://www.familyleisure.com/Above-Grou ... ming-Pools
direct link to videos http://www.familyleisure.com/customer-support
chem geek
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Cannot defeat this ALGAE!

Postby chem geek » Mon 13 Jul, 2009 21:59

If you maintained a high shock level for FC and the water is no longer green, but you can't seem to get rid of the cloudiness, especially in the depths (and assuming you've been cleaning your filter), then you could consider using a flocculant such as OMNI Liquid Floc Plus, but you'll need to be able to vacuum-to-waste to remove what settles to the bottom of the pool. Normally, chlorine and filtration will clear a pool, but if your circulation is very poor then a floc can help.
woslambert
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Cannot defeat this ALGAE!

Postby woslambert » Mon 13 Jul, 2009 22:22

The circulation is great on our pool. We have a sand filter and we backwash it anytime the pressure goes up more than 8psi. The green is still there but its very light. I took a sample to the pool store and they advised to use sodium bromide and 6 more bags of shock. That is what I put in there today and now I'm just waiting. She said the sodium bromide would bloom any left over algae and the shock's effectiveness would be increased by the sodium bromide. Its been 3 hours since I put it in and the FC is still VERY high. I can put one drop of the chlorine drops inand the water turns burnt orange immediately. She said our CYA was 15ppm but july 3rd it was30ppm and we are using dichlor so I didn't really understand that. She did get our chlorine numbers mixed up and I had to test it with my strip kit and drops kit to make sure she was wrong. About a month ago I tried some DE filter media and clarifier but my water was still minty green and cloudy.
chem geek
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Cannot defeat this ALGAE!

Postby chem geek » Tue 14 Jul, 2009 01:10

Well, the sodium bromide has now turned your pool into a bromine pool. You will have higher than normal chlorine demand for a while because the bromine does not attached to Cyanuric Acid (CYA) so will breakdown faster (though not as fast as unprotected chlorine; but faster than chlorine with CYA). The only reason to use bromide would be if the CYA were very high and the chlorine therefore not as effective (though in that case one should usually do a partial drain/refill to lower the CYA level).

If you really did shock the pool, then there should be no green. The algae would turn gray from the chlorine. So perhaps the green is something else, perhaps copper or some other metal ion.

For every 10 ppm FC added by Dichlor, it also increases the CYA by 9 ppm. You should really get your own good test kit, either the Taylor K-2006 or the TF100 from tftestkits.net. Anyway, sounds like you're following the advice of the pool store, so good luck.
woslambert
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Cannot defeat this ALGAE!

Postby woslambert » Tue 14 Jul, 2009 10:53

CHem geek- what do you mean "if i really did shock the pool"? YES I shocked the pool. We dumped over 24 bags of shock in there since Friday evening. It looks better this morning. Very little green if any at all just cloudy now. The pool store lady advised to shock again after doing the sodium bromide this evening. When I did the chlorine test this morning the drops turned it burnt orange again however not the dark burnt orange from last night so its fallen a bit.
chem geek
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Cannot defeat this ALGAE!

Postby chem geek » Tue 14 Jul, 2009 22:53

Sorry. I didn't mean to sound like I didn't believe you. I meant "really" as in "really hit it hard with a lot of chlorine that was the strength claimed on the package...". Chlorine will bleach out algae if enough is added (but will work very slowly if the CYA level gets too high). You then have dead gray algae to more fully oxidize and/or filter out. So I'm glad you got to that stage.

You are following the advice of your pool store so that's fine if it's working for you. If you want to do more yourself in the future, then get yourself a good test kit, either the Taylor K-2006 you can get at a good online price here or the TF100 from tftestkits.net here with the latter kit having 36% more volume of reagents so is less expensive per test. With these test kits, you can accurately measure high levels of chlorine (up to 50 ppm) with a precision of 0.5 ppm (with a 10 ml sample) or even 0.2 ppm (with a 25 ml sample). The kit will measure Free Chlorine (FC), Combined Chlorine (CC), pH, Total Alkalinity (TA), Calcium Hardness (CH) and Cyanuric Acid (CYA).

Pool stores are notorious at doing tests incorrectly, especially the CYA test. I don't know the size of your pool or weight of the bags of Dichlor, but if they are 1 pound each and your pool is 15,000 gallons, then 24 pounds of Dichlor in 15,000 gallons would be a cumulative FC of 106 ppm and would increase CYA by 97 ppm making the chlorine VERY ineffective (hence the need for sodium bromide). The pool store was claiming much lower CYA levels which is why I question it -- plus one should NEVER use Dichlor for shocking a pool since it add too much CYA. If your CYA level is truly high, you'll have to lower it through dilution of water (partial drain/refill) or else be stuck having to buy algaecides or phosphate remover at extra cost. Essentially, the pool store created the need for you to use sodium bromide (because they had you shock with so much Dichlor) and then now you'll be stuck having to buy even more products to keep algae from growing.

The article you initially referred to says to use chlorinating liquid or bleach (or sometimes Cal-Hypo, if your CH is low), so I don't know why Dichlor was used for shocking. I strongly suspect that the pool store's 30 ppm CYA number was wrong so the shock level was too low and now, well, the CYA is through the roof. It might be interesting to see what level the pool store now reports for the CYA.

Just in case your pool store isn't knowledgeable, the following are chemical facts independent of concentration of product and size of pool:

For every 10 ppm Free Chlorine (FC) added by Trichlor, it also increases Cyanuric Acid (CYA) by 6 ppm.
For every 10 ppm FC added by Dichlor, it also increases CYA by 9 ppm.
For every 10 ppm FC added by Cal-Hypo, it also increases Calcium Hardness (CH) by 7 ppm.
woslambert
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Cannot defeat this ALGAE!

Postby woslambert » Tue 14 Jul, 2009 23:33

Ok I noticed something today while surfing the web and I'm not sure if this is the same dichlor the article refers to. My shock bags say "sodium dichloro-s-triazinetrione hydrated 99% available chlorine 55.5% Is this the same Dichlor?
chem geek
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Cannot defeat this ALGAE!

Postby chem geek » Sun 19 Jul, 2009 02:36

Yes, that is Dichlor. Do NOT use that for shocking and only rarely for chlorine only when you want your CYA to rise.

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