View Full Version : High Phosphate 2500 - Options?

Slam Pool Guy
06-06-2006, 01:16 AM
28,000 Ga / IG / DiamondBrite plaster / SWC

Yard guy dropped what I think was fertilzer into the pool near adjacent flower beds resulting in what look like rust stains (likely from the iron in the fertilizer). A few days later I note that FC has dropped from usual around 6 to near zero. No algae yet but I know I need to move on this. Currently:

ph 7.2, FC 0, TA 70, Ca hardness 200, Na 3000 ppm / CYA 40 / Temp 86

Phosphate 2500 ppb (I suspect that this is from fertilizer).

I have already shocked with bleach and will do so nightly until this is all addressed. Have turned SWC up to 100% and have added a small amount of CYA. Will add baking soda tomorrow night to bring up TA.

What do I do next? PHOSfloc? PHOSfree? Something else?

Thanks to any and all that can help me.

Slam Pool Guy

06-06-2006, 06:27 AM
You MAY be one of the few people for whom phosphate treatment is appropriate--since it looks like somebody put fertilizer in your pool!

Search the entire forum for references, especially posts by PoolDoc-the forum's owner. At this point, his is the only advice I would trust on this--whether or not you need to act, if so what to add, and what to expect when you do.

Until then run your FC up to 15ppm and keep it there until it holds without dropping precipitously. I KNOW that this is not the best thing to do with metal stains, but you MUST make sure algae doesn't start growing. You can try ascorbic acid on the stains.

If this is advice isn't correct, PoolDoc or one of the other moderators or our most experienced members may correct me, but you should be OK doing this.

06-06-2006, 09:23 AM
Phospahte remover might not be useful right now since most fertilizers are high in nitrogen compounds also. Algae eats both of them and only lowering one won't do much good. The nitrogen compounds would be my guess as to what is dropping your chlorine.
Where is the TC?
I agree will Carl! Hit it with bleach hard and heavy right now until the FC is holding then you can deal with the other problems you may or may not have a bit later.

06-06-2006, 02:02 PM
I had similiar problem a month or so ago. I bought some Phosfloc but did not use it after asking around. I spent more money, but less hassle, on 3 (3 liter) bottles of PhosFree over a 3-4 week period. I would put in a bottle (20,000 gallon pool) and backwash appropriately (generally after about 4-5 days). I ran the pump for at least 12 hours a day. It took time, but it worked. So, the PhosFree stuff works. It will make your pool a little milky for a day or two but that clears up. Good luck...I feel your pain.


Slam Pool Guy
06-06-2006, 03:50 PM
Is there any risk to your filter with use of PhosFree? I was under the impression that perhaps the phosphate precipitates produced by the PhosFree could or would damage your filter?? I wonder if anyone can confirm as fact or classify as myth? Thanks to any and all.

06-06-2006, 04:48 PM
My phosphates also build up over time through fill water, about 300 ppm right out of the tap. When I can't keep FC in the pool more than a few hours I have it checked. The last time it was 3000+ ppm, about 3 years worth of build up.

I have found that ALUM (purchased from Leslies) is better and cheaper than No-Phos at that level, as it lowers it almost overnight. The drawback is that it's a mess to deal with. It totally clouds your pool then settles on the bottom overnight. Then you vacuum to waste, and again a day later after more settles...

06-06-2006, 09:59 PM
aluminum sufate is effective for phosphate control and is also used a a floccing agent in pool. Don't use it unless you can vacumn to waste! If you can't then the lanthenum chloride baseed products are a better choices since they will keep the phosphate precipitate in suspension in the water and your filter will remove it in a few days to a week. You need to watch the filter pressure and clean it as it rises. That is really the only danger to your filter. If the phosphates are very high the pressure can rise very fast and in worse cases the filter could need cleaning a few times a day. DE filters are probably the worst offender here.

06-09-2006, 06:14 PM
Phosphates: one of my favorite subjects.

I had them last year, paid $55 for a quart of something called Sea Klear. It worked and a problem I was having with persistent chlorimines disappeared.

This year my chlorimine problem is back as well a couple of episodes of phosphate contamination. The first episode, I choked and spent another $55 for a quart of Sea Klear and, again, it worked. But this time, my chlorimine problem has not disappeared.

In one of my more recent pool store water tests (I've had 15 water samples tested in the last five weeks -- I'm going nuts) 1.4 ppm copper showed up. I was told by the pool store that I needed a metals controller. What the heck, I bought 2 qts and poured it into my pool water. I think the stuff is known as a sequestering agent.

Since I have had so much trouble with phosphates, I bought my own phosphate test kit from La Motte. I used it after adding the metals agent and my phosphates show very high -- higher than the maximum range of my tester, which is +1,000 ppb. This is my second episode with phosphates. A little note in the test kit advised that sequestering agents are a source for phosphates. Very interesting.

Where do you other folks get tests that actually quantify phosphate content? The two different dealers who have tested my water for phospahtes used color comparators that don't quanify above 1,000 ppb.

As far as my problems with chlorimines; well thank God Almighty, I've discovered this website. In the last couple of days I have become a convert. It's the three B's for me.

I still have high combined chlorine, but as soon as I get my RS234 test kit (in a couple of weeks, I hope), I'll be able to accurately test and take the necessary steps to get things right with my pool.

There will be far fewer trips to the pool store. In fact, the grocery store is my new pool store.

In the meantime, should I try to do anything about the phosphate?


06-10-2006, 06:09 PM
Most sequesterants are based on derivatives of phosphonic acid. They can add phosphates to the pool from what I underatand. This is usually not a problems since it is very rare that phosphates are the limiting factor in algae growth. The CC are coming from nitrogen compounds like ammonia, urea, and organic nitrogen compounds, not phosphates as far as I know. Phosphates are measured in PPB and over about 175 ppb is the danger level, supposidely. I have over 1000ppb in my pool (measured with a salt water aquarium test kit that has a bit more accuracy then the one at the pool store where I work. My aqauarium kit uses a comparator block and better resolution, the one at the store a paper color card.

06-10-2006, 09:07 PM
Thanks for your reply, Waterbear.

I am understanding from your comments that it isn't necessary to worry about the high phosphate content, so I won't (no more Sea Klear for me).

Regarding the chlorimine problem I have, I am adding about 6 lb of granulated dichloro shock on a daily basis (I'm trying to use up what I've already paid for at the pool store) in order to keep my FC at a high level. I have no way of knowing how far above 5 ppm it might be, since my test kits (DPD #1 and OTO) only read to 5 ppm. I'm wondering if I could dilute my water sample with a measured amount of tap water to get a reading that shows on the color comparator, them multiply by the dilution amount. For instance, if I add one tablespoon of pool water to two cups of of tap water, I would have a dilution of 1:32. If the diluted sample read 1 ppm, them actual FC content could be derived by multiplying 2 ppm X 33. Do you think this would work? I need to find someway to quantify high FC content until my RS234 kit arrives.

I want to achieve "breakpoint" chlorination and I understand this requires raising and maintaining (for one week) FC levels that are 5 to 10 times the chloramine levels. In my most recent test at the pool dealer, my CC was 3.2. I guess that means I need to maintain FC for one week at 16 to 32 ppm. Am I thinking correctly?

I've drifted pretty far from from the phosphate issue, but that's what started all this. If I'm incorrectly posting, I'm sure one of the Super Moderators will let me know.

Anyway, this forum and PoolSolutions.com have moved me from very deep dispair only one week ago to where I feel pretty darned confident that I can get things right at last without spending yet another huge lump of $$$.

My best regards to all who help folks like me. I have learned so much in such a short period of time.

06-10-2006, 10:09 PM
What is your CYA level? Using dichlor or trichlor is driving it up, and depending on how high it was to start, you may have to go higher than you think with the Cl to get rid of the chloramines.


06-10-2006, 10:56 PM
you can use the dilution method if you use distilled water:

Here's the Jen-You-Whine CarlD Shot Glass Method!;)

1) Get a shot glass (like you use to mix drinks).
2) Get a gallon of steam distilled water--most mass-market drug chains stock it, and many supermarkets.
3) Mix one shot glass full of pool water with one shot glass full of the distilled in a clean container (like a Pyrex measuring cup).
4) Fill your test cell to the line with the mixture. Add your drops and take the reading.
5) Whatever you read, double it. If it says "3ppm", you have 6ppm. If it reads "5ppm", you have 10ppm.
6) If it's STILL seems like the chorine's too high to read, go to step seven....
7) Mix 1 shot of pool water with TWO shots of distilled water, and re-run the test using that.
8) Now TRIPLE your reading--if it reads "3", it's 9. If it reads "5", it's 15ppm.
9) Going beyond two shots of distilled to 1 shot of pool water is possible (3 shots, quadruple your reading) but you lose accuracy fast. Still if it's the best way of reading chlorine, then you have to do it.

CAVEAT: ONLY use this method to measure chlorine levels. Do not use it for the other tests you run, and do not use it with the FAS-DPD powder test--that goes to 50 to 100ppm of Free Chlorine anyway.

There you have it!

06-11-2006, 12:02 AM

I have no way of knowing how far above 5 ppm it might be, since my test kits (DPD #1 and OTO) only read to 5 ppm. I'm wondering if I could dilute my water sample with a measured amount of tap water to get a reading that shows on the color comparator, them multiply by the dilution amount. You can diliute and in fact it is a standard procedure with both OTO and DPD testing (DPD bleaches out at high levels of chlorine) but I would not go over a 4:1 dilution. With each dilution you lose accuracy. Easiest way is to use a shot glass or some similar measure and dilute with distilled water.....
for a 1(pool water):1(distilled water) dilutiion multiply reading by 2
for a 1(pool water):2(distilled water_ dilution multiply reading by 3
for a 1:3 multiply by 4
for a 1:4 multiply by 5

for how high you need to go with your chlorine it is somewhat dependant on your cya levels ....see this post for details on how high to bring your chlorine up to shock effectively and get rid of the CC.

06-11-2006, 12:03 AM
Hey! That sounds mighty familiar!:confused:

(Glad I didn't have to type it again!;) )

PS: I am flattered!:rolleyes:

06-11-2006, 12:15 AM
I am a BIG supporter of the patented 'CarlD shotglass method":D!

06-11-2006, 08:39 AM
10) Rinse glass nicely
11) Fill with favorite spirit
12) Savor spirit while admiring beautiful pool!