Phosphates??

crokett

Well-known member
Jul 17, 2007
535
Hillsborough, NC
#1
I have yellowish water (clear but yellowish) and thought it was metals and the sequestrant wasn't working. I took some of my untreated tap water in and the pool store said it was high in phosphates - 450- 500. He said that happens in my area a lot. He said to keep treating as normal and in the next few days the color should disappear. He also noted that phosphates are food for algae. I had a terrible problem with algae last summer. I did a little research and find that the phosphates have to break down in the water before the algae can eat them, and that they start to grow in pools (even treated ones) at the levels I have. This is consistent with what happened last year - a few weeks after I filled the pool is when I started having algae problems, literally overnight.

So should I treat to remove them or just let them balance? I am concerned because we will be gone for 6 days next week and then gone for 8 days in July. I'd rather not have to fight algae again and will do whatever I can to prevent it.
 
G

Guest

#2
Phospahtes are only a problem in algae blooms if they are the limiting factor in algae growth. Very rarely is this the case. Phosphate removers are a big scam that pool stores use to sell another product that you don't really need in 99% of the cases.
 

JasonLion

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May 7, 2007
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Silver Spring, MD
#3
You should just ignore everything you have been told about phosphates. Half of it is wrong and the other half is misleading. If you maintain proper FC levels you won't get algae, regardless of your phosphate level. The phosphate level in my tap water is several thousand and I don't have any problems. The pool stores have been pushing phosphate remover as a way of making more money. In any case yellow water wouldn't have anything to do with phosphates.

It would be a huge help if you could post a full set of water test results. That might help give us an idea of what might be happening. Also, do use well water to fill the pool or are you on municipal water?
 

crokett

Well-known member
Jul 17, 2007
535
Hillsborough, NC
#4
I am on well water.

pH is 7.6
TA is 130
Free Chlorine is 3.2
CYA is 30
CH is 100 (I think, pool place print out recommended I treat, but I have vinyl pool so thought that is an ok level)

Pool place says iron is high in my tap water but don't remember what the level is

History is last year I had colored but clear wate and fixed it with a sequestering agent. That was yellowish/brownish - cinsistent (I think) with chlorine reacting with the iron. Then I had severe algae problems and fixed them using BBB. This year while filling I added the sequestering agent. Water was sparkly until I started adding chlorine, now water is clear but yellowish/greenish. Pool place said yesterday this could be phosphates and should go away on its own. Is this correct?
 

JasonLion

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May 7, 2007
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Silver Spring, MD
#5
No, the yellow isn't because of phosphates. It is almost certainly caused by iron in the water. Most likely you didn't add enough sequestrant. Lowering your PH to between 7.2 and 7.4 can help to clear it up more quickly, but the long term solution is to maintain the correct sequestrant level.
 

crokett

Well-known member
Jul 17, 2007
535
Hillsborough, NC
#6
Hi Jason,

I added a different brand sequestrant at a little more than the recommended dosage. It was the only brand that told me to double the initial dosage if there were existing discolouration deposits or discoloured water. The others give you an initial dose or a maintenance one. I will see what that does. Meantime I will continue shocking nightly which is what I am having to do to keep chlorine levels up.
 

JasonLion

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#7
Testing and raising FC to shock level once a day is not enough to effectively fight algae. You need to test and raise FC back up to shock level at least twice a day and preferably more frequently than that if you want to kill the algae.
 

bassadict69

Well-known member
May 27, 2007
148
Benton, La
#8
I agree with what the others have said...don't worry about phosphates unless it is a LAST resort & nothing else will keep the algae away.

I do not agree on the part about algae not growing if you keep your chlorine up...that is not always true. I have extremely high phosphates & spent years fighting one algae outbreak after another. Even after finding the BBB method & reading up, I still had the algae outbreaks several times per summer...EVEN AT EXTREMELY HIGH CHLORINE LEVELS...I have the bleached liner to prove it! I got fed up & dumped LOADS of bleach into the pool. It bleached my liner but the water stayed green.

Keep in mind what I said about worrying about phosphates only as a last resort! After several years I decided I was at the last resort & decided to try the phosphate treatments...phosfloc & phos free! I can attest you don't want to go this route unless exremely necessary! The phos floc is nasty & very time consuming...but, If I do it once per summer, my water is alot easier to manage & I can keep the water clear.
 

crokett

Well-known member
Jul 17, 2007
535
Hillsborough, NC
#12
There is no algae - yet, but if this goes on much longer there may be. The metals are still eating a good chunk of my chlorine. You guys were correct (again) :-D I added a different brand sequestrant yesterday and it lightened the water considerably. I will get another bottle tomorrow and see if that finishes the job. What I really want to konw is why the first bottle didn't work. I will also vac out the pool tomorrow. It doesn't need it yet but I am paranoid.
 

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bassadict69

Well-known member
May 27, 2007
148
Benton, La
#13
Matt said:
bassadict69, were your CYA levels high too? (Edited for clarity. JasonLion)
No, CYA levels were right around 50ppm & I was holding chlorine levels just above 20 for over a week with no improvement at all...filter running 24/7 also.

Noone was able to tell me how high the phosphate were...when using the blue comparator type test, it was almost black...WAY darker than the darkest blue on the comparator chart.

It took 3 phosfloc treatments in one season to bring them down to manageable levels. My biggest problem is that my fill water is high in phosphates so everytime I would top off the pool after vacuuming the fluffy settled stuff from the phos floc, I was adding more phosphates back to the water. Phos free was also being added to the water while filling & is now added weekly.
 

chem geek

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Mar 28, 2007
12,082
San Rafael, CA USA
#14
The maximum on the test is 1000+ so it was probably very, very high. We have pool users who are able to manage their pools with chlorine alone in the 1000-3000 ppb phosphate range and we had one user with a confirmed 7000 ppb phosphate level where it could not be easily managed with chlorine so this is why I give a rough rule of 3000-4000 ppb as being the possible level where the chlorine/CYA chart starts to break down (i.e. require higher chlorine levels and become not worth it), but it's just an estimate.
 

akelley

Active member
May 17, 2008
36
#15
Crocket, what were the two brands of sequestrants you used? I'm looking at getting some myself and wondered if there really much difference between the brands.
 

crokett

Well-known member
Jul 17, 2007
535
Hillsborough, NC
#16
I used Metal Free and Sea Klear brands. The Metal Free worked just fine last year. The Sea Klear is half the price. Yoiu use a little more but it is still cheaper. There may be something else going on. In the last 3 days I've added a triple dose of Sea Klear and the best I can do is get the water back to a very pale yellow, as compared to tap water. I finaly realised the water looks greenish because the vinyl has blue in it. :roll: I pulled a sample out of the pool and compared it to tap water and the pool water is clear, but a pale yellow. The Sea Klear needs a specific pH range as per the bottle. Mine was low so I raised it last evening and retested before putting the Sea Klear in.
For grins, numbers as of this morning:

ph 7.6
TA 130
CYA - 35
Calcium - ( the Sea Klear needs a specific range) 150
Chlorine is high but I shocked overnight.

Do I need more sequestrant? I can't get the color out. Last year it was a single treatment overnight and it was fixed. This year I've treated 3 times now and it is still colored.
 

crokett

Well-known member
Jul 17, 2007
535
Hillsborough, NC
#18
Yes, Sea Klear Metal Klear. Looking at the MSDS on it and it only mentions an acrylimide-acrylic acid copolymer. I dod some research and google turned up a thread on this site (is there anything TFP doesn't know about pools?) that looks like what I need. I will read that thread - first glance says Metal Klear does not appear to be what I want.
 

duraleigh

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Apr 1, 2007
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Sebring, Florida
#19
Crokett,

This is just a thought but for a pool with 3200 gallons, have you considered draining completely, refilling and then putting in one quart of bleach each evening and then go swimming? It's all you'd ever need to do for less than 50 cents per day
 

crokett

Well-known member
Jul 17, 2007
535
Hillsborough, NC
#20
duraleigh, that is what I am doing now and normally I am happy doing that but

a) this pool holds more and I will probably fill it full (approx 4400 gallons) next season
b) my wife is already making noises about a larger pool :)

So I want to do it right. Besides, I'd like to swim in water-colored water as opposed to uhhmm, yellow-colored water. :wink: