Sorry Another Phosphate Question

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K

Kjp300

Gold Supporter
Jul 18, 2018
189
Canfield ohio
Pool Size
23000
Surface
Vinyl
Chlorine
Salt Water Generator
SWG Type
Hayward Aqua Rite (T-15)
Well I shouldn’t have done it but I went ahead and tested my phosphates today with the Taylor kit and based on the color comparator it looks like they are in the 3000ppb range. I am aware of the debate regarding removing phosphates and haven’t decided yet whether or not to do it. If I decide to do it it won’t be until the end of the season because of the cloudiness and having to clean the cartridge filter etc. My water is TFP clear and I always keep my FC at the high end based on my CYA.

I bought the test kit a few years back and when I first tested for phosphates it was in the 500ppb range. So my pool is getting phosphates from somewhere and assuming I do not remove them I can also assume they will continue to increase. I know nothing about chemistry but my common sense tells me that once the phosphates reach a certain amount that it doesn’t matter if it is 3000ppb or 30,000ppb because the algae can only consume so much. Is this true? The reason I ask is that if I decide to remove the phosphates it only makes sense to try to get the amount to zero. If I cannot do that why go through the hassle?

I don’t want to reignite the debate on removal, I need to decide that. But I guess I am really asking if the amount is not zero or some ridiculously low amount does it even matter how much is in the pool?
 
If FC is maintained at proper levels, phosphate levels do not matter.
If you regularly allow your FC levels to fall below minimum, removing the phosphate gives a bit more time to recover before you get an algae outbreak.
 
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Below 1000ppb is fine. Less is always better. At 3,000ppb and above, you are giving algae all the fuel it needs to bloom if your FC drops below minimums. At 3,000ppb on a 22k pool your going to need a bit over 1 quart of commercial grade remover to get near zero. So you’ll likely have to buy 2 quarts or maybe a gallon depending on how the prices work out. A cartridge filter is not the best for removal but it’s what you have. If it takes too long to clear you may have to help it along with a clarifier but I’d rely on the filter itself first and see where you go. The process could mess up your filter cartridges so you may want to price out new cartridges to see if that’s worth the cost.

Good luck & keep the thread updated.
 
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Thanks for the reply’s. I understand that if I keep my FC levels above the minimum I should be ok. I always keep my FC on the high end because after finding TFP and with a few years of managing my pool, I find that the water quality is still outstanding. I really think that most people here get themselves in trouble trying like crazy to keep the minimum FC they can when it really doesn’t matter if you keep on the high end.

As far as my phosphates I would like all members to offer an opinion on whether I should try to reduce my phosphates or not. Just as an informal poll. I am leaning against it. But perhaps Matt can help with my question. Does it matter if it is 3000ppb or 30,000ppb? Is there a point where it doesn’t matter because the algae can only consume so much? I know if I let my FC drop below the minimum right now I could have a problem. But beyond that does it really matter what the phosphate level is?
 
You definitely don’t want 30,000ppb (30ppm) phosphate. Not only is that a huge nutrient load but it’s also likely to cause calcium phosphate scale inside your SWG if your calcium hardness is high enough. Calcium phosphate cannot be removed.

Any phosphate level over a few hundred ppb is considered nutrient rich (eutrophic). Algae growth will generally follow phosphate concentration and so higher levels will lead to faster growth. Algae are short lived organisms and will die off as rapidly as they grow leading to very fast increases in biomass. This is why water can turn green very quickly. Once there’s enough biomass to keep the cycle going, chlorine gets used up as quickly as it is added and you have to SLAM to get rid of algae.

You need to investigate your phosphate source. Check you municipal water supplier, are they adding phosphates? Do you use fertilizer around your pool? Grass clippings? Lots of tree debris? It’s coming from somewhere and if you don’t identify it, you’ll be constantly fighting it.
 
I have a hunch it is coming from fertilizer. We have a lawn service. Once after an application my auto cover had so much fertilizer on it I though they meant to fertilize my deck and pool. I have since had a conversation with the company but one or two applications with the cover open may have done the trick. Grass clippings are sometimes a problem because the pool is used by my grandkids who live next door to me and all of their neighborhood friends. Other than that I will test my fill water but with the cover I get very little debris in the pool.

Matt, thanks for the responses. And I assume by your answers you think I should lower my phosphates. I think I will try at the end of this season. I figured I might need new cartridges and I am going to order the Orenda 10,000 to do the job. I will get back to you when I try. But does it make sense to do it in steps? Put enough in to lower it a little, let the filter do its job, clean the filter and repeat? Or dump enough in all at once to lower it below 1000 and deal with the filtering only once? I would be interested to hear from others who have gone through the process. Thanks!
 
When I installed my pool, one of my co-workers was an anti-phosphate fanatic. He made me a believer. I used Phosfree and Phosfloc for years. All it did was make my pool cloudy and then I used clarifier. And then I had to clean my cartridges.

Since I joined TFB, I have not cared. 3,000 seems REALLY high. Maybe this is a case to get it out. And then prevention.
 
Just do it all in one treatment, no need to do it in steps. If you aim for zero phosphates, you’ll get close enough. The lanthanum chloride converts to lanthanum carbonate and lanthanum phosphate, so as long as you let it filter until the cloudiness is gone, none of the product will remain in the pool water; it will eventually all go away.

If it were my pool and my phosphates were 3000ppb, I would treat that. Currently my pool is around 250ppb and it’s been that way for a long time (no fertilizer, no phosphates in fill water, only natural phosphate accumulation).

FYI - human urine has a significant concentration of phosphates in it. Children are not very good about toileting before pool use (neither are many adults …). You have lots of people in your pool. If A = B and B = C then A = ??? … Just sayin’ ….
 
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Jumping on the thread. My phosphates were on the high side (2,000+). I treated last night and now have white powder on the floor of the pool (looks like it came from the return jets). Should I leave them alone, vacuum with my robot, manually vacuum then backwash (sand filter), or vacuum to waste? Thank you!
 

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Those are the phosphates. You need to remove them from your system or they will reintroduce themselves. Vac to waste. Also clean the filter after a couple days.
 
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