Newbie Here. Question with Phosphates and FC/Cya Ratio

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K

kdiamond

0
Sep 12, 2013
25
Orange, TX
I have a new pool that is one month old. 18,500 gunite with pebble plaster. I hear conflicting stories regarding phosphates in pools. My chlorine levels went to zero this week. Pool builder said check phosphates because it can cause low chlorine readings. I have several questions for you guys/gals.

1. Should I even be concerned about phosphates levels if I have no visible algae. Does high levels consume chlorine? I have borates in the pool and that is supposed to help with Algae, right?

2. I see on here about FC to CYA ratio. Is that something I should go by? Of course, no local pool company has ever heard of it here. I have an ozone system, does that change the ratio?


Also, I live in SE Texas and water temp stays around 90.

Thanks,
Kurt
 
Welcome to tfp, kdiamond :wave:

Phosphates don't matter in a properly chlorinated pool...unfortunately, yours isn't properly chlorinated since your FC is at 0 ppm. Phosphates are food for algae, so if you maintain proper chlorine levels then algae can not grow and phosphate levels are not important. Algae do not have to be visible to be in a pool...we see/hear examples all the time. How are you chlorinating your pool, i.e. what is your inline chlorinator, a puck feeder?

kdiamond said:
2. I see on here about FC to CYA ratio. Is that something I should go by? Of course, no local pool company has ever heard of it here. I have an ozone system, does that change the ratio?
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Yes, follow the Chlorine/cya chart recommendations. If you can turn off the ozone, I would...ozone is not needed in a typical outdoor residential pool. If you leave it on, it will likely just require you to add more chlorine since the ozone will destroy some.
 
Welcome to TFP.

Phosphates do not consume chlorine. Unfortunately we have heard of it. And it's no truer now than it was the first time someone asked about it. :(

In a properly chlorinated pool you will have a level of FC regardless of other things. If you don't have any FC then it's not sanitary.

You should seriously consider reading Pool School, getting a good test kit and following the method taught here and you'll have a truly trouble free pool.
 
bama beat me, here are my comments:

kdiamond said:
Yes, I have an inline puck(trichlor). Pool builder told me I wont see any chlorine level till the phosphates come down. Have you ever heard that?
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Your pool builder is clueless when it comes to pool chemistry. Of course you could add enough chlorine (if you add enough fast enough) to get a measurable level, but if you have algae, then the chlorine will get used up quickly killing it.

For your normal chlorination source we do not recommend using a puck feeder. It adds cyanuric acid (stabilzer) in addition to chlorine. See this pool school article: http://www.troublefreepool.com/pool-school/types_chlorine_pool

Have you added any cyanuric acid (aka stabilizer, conditioner) to your pool besides that which comes from the trichlor pucks? How many pucks have you and the pool builder used on your pool?
 
Currently, as of this morning:

Chlorine: 0
PH: 7.0
TA: 80
Hardness: 210
Cyn: 70

I added 3lbs of shock this morning and my chlorinator has probably used 2 complete pucks during the last 30days.
Pool has no algae present but has 2500+ of phosphates which I treated for that yesterday at the advice of local pool supply.
.
 
Forget the phosphates (too late now).

What was the magic powder that you used? It may have added more CYA and yours already appears to be too high which will require a water change to correct.

Where did these results come from?
 
First off welcome neighbor across the river, second off what these guys have said is true. While it is true that Phosphates promote the growth of algae (it is algae food), and lowering Phosphates through the addition of expensive phosphate removers can help in an out of balance pool where algae is trying to get started growing, however our point here is in a properly balanced pool with the correct FC/CYA ratio algae can not grow, so addition of this expensive phosphate remover is not needed. Also while Phosphate remover can help delay the onset of an algae problem, once one starts it does little good in clearing it up, this instead requires chlorine. As far as getting pool management advice from a pool builder, this is sort of like getting medical advice from the guy that built your local hospital, as the simple fact is many pool builders have little or no experience managing pools after the initial start up. Another important thing to remember is that maintaining proper chlorine level is not just about maintaining an algae free pool, but also about preventing all those other less visible types of micro organisms from growing in your pool (bacteria, etc.), so while phosphate remover may help the visible algae problem it will also tend to cover up the non visible problems caused by having too low of FC/CYA ratio level. As to your Ozonator, this is again more snake oil, at least for the conditions you likely have, while it is true Ozonators do provide supplimental oxidation, which may be needed in some very high bather load commerical pools, indoor pools, hot tubs, etc. The simple fact is the typical outdoor residential pool, particularly in our sunbelt region will get more than enough oxidation potential from sunlight, even if located in a partly shaded location. So unless you have a very shaded pool with one continous swim party with dozens of swimmers going all summer, then the Ozone system is doing nothing for you except needlessly increasing your Chlorine consumption. (I know lots of people are sold Ozone systems under the sales pitch that it will reduce chemical costs, but the truth is in a correctly balanced pool all it will do is increase chlorine use, like many of these topics there is some half truths in this marketing, as it might reduce your chemical consumption if you are continously battling algae bloom, etc. caused by having an out of balance pool)

Ike
 
The LPS loves to sell phosphate killing stuff since they can then also sell you a chlorine-product to kill the algae the phosphate "feeds". Sort of kill the algae AND kill the phosphate. The solid forms of chlorine are more profitable for them, so they encourage you to use them. Liquid chlorine is typically one of the lowest margin products they sell, based on my experiences.

You need to stop using Pool Store methods and TFP methods at the same time. TFP focuses on killing the algae by using chlorine, either liquid or salt-generated. With no algae, your phosphates are completely unimportant sine there isn't any algae to use it and no reason to buy a chemical to remove what doesn't matter.
 
Thanks Guys,

Jason... The results came from LPS. I used 20oz of Orenda PR-10,000 phosphate remover. I will not worry about Phosphates anymore. I did have a lady that owns a LPS close by my house that she don't even test for it because it is just another chemical to sale. I thought that was pretty honest, since she can sale Phosphate Remover. What is your thoughts on this?I have had several LPS tell me that in our area that CYA can be up to 80-100 in our area. Do you think mine at 70 is too high and I need to do a water change?
 

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The high CYA is mainly an issue of you get an algae bloom. If your need to SLAM the pool with an 100CYA, you need 39FC or about 8 gallons in your pool. With a 70CYA a SLAM would require 28FC or about 5 gallons and if your CYA is closer to 40, it would only take 16FC or 3 gallons of 8.25%. These are rough number assuming you were starting near 3FC.

Once you get these levels, you need to keep your FC near your SLAM level until the algae is and other organics are removed and you pass your overnight testing (OCLT). See the Pool School link above for more details.
 
70-80 is good if you have a SWG (Salt Water Chlorine Generator), A CYA 70 to 80 for a manually dosed chlorine pool, is maintainable, but is asking for trouble if you EVER let it slip and have an algae bloom as you appear to be having or are about to have now. In general we consider anything over 100 to be unmaintainable, 70-80 is marginal, and asking for trouble if things ever slip because it will require a tremendous amount of chlorine, time and patience to clear, 40-50 is far better as while it may increase chlorine demand a little, it also makes clearing algae blooms much easier if/when they happen.

Ike
 
Firstly, I will throw in my "Welcome to TFP :wave: "
kdiamond said:
I did have a lady that owns a LPS close by my house that she don't even test for it because it is just another chemical to sale.
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That is the pool store you will want to go to when you need stuff that you can only get at the pool store. While you won't need much chemicals from them, if they carry hoses and other hardware I would send business their way. Do they carry liquid chlorine by chance? It is sometimes a good value to get the higher concentration of chlorine from a pool store that carries it.

As for your CYA, it depends on whether you wish to continue to use pucks to chlorinate. If you wish to continue using them you should bring your CYA down to 30ish and maintain it between 30-50. The pucks will constantly raise your CYA so you will have to remove some water fairly regularly to counter that. If you are considering changing to a new method, such as a Salt Water Chlorinator or manually/automatically adding liquid chlorine you can probably handle your CYA around 70. No matter which you choose you need be sure to maintain your FC based on the FC/CYA table. Your own test kit would be very helpful, I have a link in my profile to a very good one, the TF-100.

Finally, personal opinion: I would disconnect the ozonator. You probably won't be able to tell any difference except it will be easier to maintain your FC level. On an outdoor pool the sunlight tends to do everything that ozone can do anyway.
 
Ok, I have decided that I will use the liquid chlorine route and turn the chlorinator off. All the Phosphate issue came to light when a Leslies store tested for it and showed high, then next morning I tested water and showed 0 chlorine. Just so happened that my pool builder was at my house getting a stain off of the tanning shelf and he said to get the phosphates down because it was eating the chlorine. At that time the water was clear with no algae present. So, taking his advice I have added the phosphate remover yesterday and added some shock. Anyway, lesson learned. I have a test kit coming and will go by the recommendations on here. I have borates, can anyone tell me if it is worth having?
 
One more comment on CYA level buildup in our region, the amount of CYA build up that we see in typical outdoor pools in our region greatly depends on the amount of rainfall we get in the summer and therefore water replacement. So in dry years like this one you will see a lot more CYA buildup than in our typical years filled with afternoon thermal thunderstorms.

Ike
 
borates are mostly good as an additional buffer for the pH ... meaning it prevents the pH from changing as fast/easily. What level of borates do you have? At least your TA seems to be reasonable so you will not struggle trying to lower it because of the borates.

Secondary effects of the borates are people thinking it makes the water feel nicer and look more sparkly ... pretty subjective. It can also be a mild algaecide and help prevent algae if your FC gets too low, but you should not rely on this.
 
You may have a hidden algae problem, under ladder steps and inside light niches are common places for this to hide, anywhere that has poor water circulation. Someone just posted a thread the other day (which I can't find) showing gobs a black /green gunk behind their pool light, this was after a long search for what was causing excessive chlorine consumption and no visible algae.

As to borates, the opinions on them are mixed
 
Thanks Jason and Ike. Hey Ike, what part of SW LA are you in?

Got one more question for you guys. With my CYA being 70. My min FC should be a 5 based on the proper ratio. How come it seems like the local pool stores all say 1-4PPM. I guess the ration just seems high to a new person that been told otherwise. I don't doubt it all, just wondering why mainstream LPS never mention the FC/CYA ratio?
 
Because either they are ignorant of the science and do not understand the CYA/FC relationship ... OR ... they ignore it so they can sell more stuff to try to fix the pool.

It is not just pool stores, there are rules from the government about what product labeling can say which is a max of 4ppm ... but this too is a holdover and lacks the understanding of the science which has been around since the 70s.
 

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