Phosphates - do I treat?

pandan74

Active member
May 16, 2020
31
Tucson, AZ
Moved from here.
Phosphates are algae food. If you kill all the algae, phosphates do not matter.

Be aware that Pool Store phosphates tests are not that good and they will try to sell you cheap phosphate removers even with very low phosphate levels. If you are concerned about phosphates, get the Taylor K-1106 test kit. Then if your phosphates are well over 2000 ppb, you may want to treat for them. I see you stated above 2500 ppb. If that was a pool store test, I would be wary of it.

I am a new guy in the pool "business" but I am an experienced biologist, more, a microbiologist, and according to my knowledge if you kill algae with... anything (it does not matter how you kill them) you actually release more phosphate (other phosphate source can be bird poops, decomposing leaves, actually any organic matter). Having said that, I am not sure how to translate this to the pool maintenance. Also, it is true that phosphate is "feeds" algae (and some bacteria). It seems like the more phosphate you have the less effective chlorine is and you need to keep higher chlorine level. Is there a level of phosphate that I should start thinking to treat it? Right now I have phosphates level 600 with FC level 6.7 and still have algae growing on the walls of the pool ( other results: TC 7.1, pH 7.9, TDS 1200, CYA 102). Please!!! do not take it wrong, I do not undermine anybody knowledge. It's rather a question and a discussion to educate myself.
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
37,085
Laughlin, NV
Pool Size
6000
Surface
Fiberglass
Chlorine
Salt Water Generator
SWG Type
Pentair Intellichlor IC-40
It seems like the more phosphate you have the less effective chlorine is and you need to keep higher chlorine level.
That is not correct. If there is no algae, which is what TFPC is built on, then phosphate does not matter.

In Arizona, phosphates could be added primarily via your municipal water system. If your phosphates go well above 2000 ppb, and are tested using a real test kit, then you might wish to treat for them.

Your current condition is you have algae, so you need to follow the SLAM Process. First, you need a proper test kit so your CYA can be determined and if you need to drain and refill your pool to reduce the CYA.
 

pandan74

Active member
May 16, 2020
31
Tucson, AZ
That is not correct. If there is no algae, which is what TFPC is built on, then phosphate does not matter.

In Arizona, phosphates could be added primarily via your municipal water system. If your phosphates go well above 2000 ppb, and are tested using a real test kit, then you might wish to treat for them.

Your current condition is you have algae, so you need to follow the SLAM Process. First, you need a proper test kit so your CYA can be determined and if you need to drain and refill your pool to reduce the CYA.
I am working on this... My CYA was 140 now is around 100. I need to go a bit lower, however I have been told that in southern AZ (not entire AZ) CYA level should be higher. Right now we have 105F and over 12 hours of sun.
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
37,085
Laughlin, NV
Pool Size
6000
Surface
Fiberglass
Chlorine
Salt Water Generator
SWG Type
Pentair Intellichlor IC-40
If you do not have a SaltWater Chlorine Generator, I would not go over 50 ppm CYA. If the FC loss is too much, you can go to 60 ppm but only until August.

Can you fill out your signature?
 

Saturn94

Well-known member
Mar 11, 2015
1,099
SE Virginia
Pool Size
20000
Surface
Vinyl
Chlorine
Salt Water Generator
SWG Type
Hayward Aqua Rite (T-15)
Your FC level is too low for your CYA level, hence the reason you have algae growing.


With adequate chlorine, algae will be killed, and no amount of “food” will bring it back to life.
 
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pandan74

Active member
May 16, 2020
31
Tucson, AZ
Your FC level is too low for your CYA level, hence the reason you have algae growing.


With adequate chlorine, algae will be killed, and no amount of “food” will bring it back to life.

This chart is very helpful. Thank you. I will try to lower CYA to 60 so I can keep FC a bit lower (and phosphates will be diluted at the same time)
 
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mguzzy

Gold Supporter
Howdy Pan!
There's a biologist in our midst. Yeah.. a pool is about as artificial a biome as you will encounter. The TFP ideal is no algae means there is nothing to eat any of the other nutrients that may be in there. . But the limnologist in me says.. there is always something alive in there... albeit just not a lot. The physicist in me says this is not a steady state system so get over it. ;) Phosphates are generally considered to not be a big deal if the algae is kept in check with properly managed Cl. So, its not considered a standard part of the TFP protocol. But you are right, if the there is a continual source of phosphates then it doesn't take much algae to overwhelm the balance. So there are those that will manage phosphates as a part of thier seasonal pool startup. That's what I do, I have a lot of trees and raised garden areas that potentially drain into the pool in the winter. I find it easier to manage things if I do a little phosphate treatment when I do my soft open in the spring. Also there is anecdotal evidence that high phosphates may affect the performance of SWG cells. There are discussions about all that scattered about on the forum. But if you do do a phosphate treatment search for the best way to do it. The removers leave a flocculant that gums up your filters.

In the meantime, it sounds like you need to get your CYA down and perform a SLAM Process. Phosphates of 600 is not really a lot in the big picture. The bigger issue is your CYA is too high and is not allowing the FC to sanitize. Too much Cl is locked up in the high CYA.

Also, how are you testing? The forum has standardized on the Taylor kits, The TFTestkits are highly recommended. Test Kits Compared

BTW you would enjoy a stroll through the Deep end forum where the hardcore chemistry background of this approach is discussed.
 

pandan74

Active member
May 16, 2020
31
Tucson, AZ
Thank you for your detailed reply. Yes, I would love to discuss the ecology of the pool but I think others can be really bored ;). I am a first time pool owner (as of 5 weeks ago) and also new to southern AZ (and to the country as a matter of fact). I have been told that in AZ we need to keep higher CYA but now I am learning it's not true, and I am working on bringing down the level fo CYA to 50-60. As I was introduced to the CYA/FC chart today it looks like with lower CYA, lower FC will be more effective. Every day something new.

What about iron and cooper level. Should I be worry (Fe - 0.1, Cu - 0.3)?

Thanks a lot!
 

mguzzy

Gold Supporter
Thank you for your detailed reply. Yes, I would love to discuss the ecology of the pool but I think others can be really bored ;). I am a first time pool owner (as of 5 weeks ago) and also new to southern AZ (and to the country as a matter of fact). I have been told that in AZ we need to keep higher CYA but now I am learning it's not true, and I am working on bringing down the level fo CYA to 50-60. As I was introduced to the CYA/FC chart today it looks like with lower CYA, lower FC will be more effective. Every day something new.

What about iron and cooper level. Should I be worry (Fe - 0.1, Cu - 0.3)?

Thanks a lot!
Pool Ecology sounds like a perfect thread for the Deep End forum. ;) yeah, the members in the southwestern states find holding the CYA on the high end of the range works better. Probably due to higher temps and UV in the region. Do you have a SWG? It would be very helpful if your equipment was listed in your signature and we could reference it at a glance. If you are having a challenge figuring out what it is, post some pics and we can tell you. that is not that uncommon with first time pool owners that bought a house with a pool.
As to the high metal reading.. yeah that is of concern. But since you just inherited the pool you may not know any history about how it was managed in the past. ie what additives were used to treat it that had those metals. A partial drain/refill will help with that as well as the CYA. How did you get those readings by the way?
 

pandan74

Active member
May 16, 2020
31
Tucson, AZ
Pool Ecology sounds like a perfect thread for the Deep End forum. ;) yeah, the members in the southwestern states find holding the CYA on the high end of the range works better. Probably due to higher temps and UV in the region. Do you have a SWG? It would be very helpful if your equipment was listed in your signature and we could reference it at a glance. If you are having a challenge figuring out what it is, post some pics and we can tell you. that is not that uncommon with first time pool owners that bought a house with a pool.
As to the high metal reading.. yeah that is of concern. But since you just inherited the pool you may not know any history about how it was managed in the past. ie what additives were used to treat it that had those metals. A partial drain/refill will help with that as well as the CYA. How did you get those readings by the way?

I finally took some pics of the pool and the equipment. Can I post them right here or there is other place? I actually have also some questions about the Pentaire and how to program it.
 

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pandan74

Active member
May 16, 2020
31
Tucson, AZ
There is a little picture icon that will allow you to upload pics to your post. I like to show them as thumbnails so they don't take up the whole page in the post. But will expand when you click on the thumbnail
OK, here are pics of my pool. It's a small pool ca 9000 gallons. There are an in floor cleaning system (I think).
IMG_4919.jpgIMG_4918.jpgIMG_4917.jpgIMG_4916.jpgIMG_4915.jpg.IMG_4914.jpg
 
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