Pool Perfect + PhosFREE

[duraleigh]

If I don't control my Phosphate level, I will get algae guaranteed.

Well, that's just not correct. You get algae because you have inadequate chlorine levels.

To suggest that low phosphate levels prevents algae is a disservice to your fellow forum members.

Algae cannot exist in the presence of adequate chlorine levels. If you get algae, your chlorine is inadequate.

Once that basic principle of pool water maintenance is understood, and once the pool owner is willing to accept it as fact, keeping your pool crystal clear suddenly becomes quite simple.

Ignoring that basic premise condems you to visit after visit to the pool store buying whatever they suggest.

 

[MikeInTN]

I've been using Phosphate remover every other week (~1 oz) to keep it below 100. This is the first year that my pool has zero algae. I have a salt water pool.
FC:2.5
CC:0
pH:8
TA:120
CH: 280
CYA: 80
Salt: 3200
Phosphate: <100

I don't use Phos-Free that was recommended by Leslie's because it adds CH. I bought one made by HASA, and its called Phos Out. Stuff works great. If I don't control my Phosphate level, I will get algae guaranteed.

I respectfully disagree. If you maintain the proper FC level, you won't get algae, regardless of what your phosphate level is.

One thing we tend to overlook as we get so focused on killing algae is that the free chlorine in your water does more than just kill algae; it also kills bacteria and other nasties in the water from things such as bird droppings, etc. All the more reason to maintain the proper FC level in your pool.

 

[Charlie Wathen]

I respect your opinions on Phosphates; however, if I let them climb over 800 or so, then I have to raise my chlorine level higher to compensate for the added algae food. I have no idea why I get Phosphates since I don't have any leaves or other organic matter falling in the pool. If I let it go for 3-4 months, my pool will begin to have issues with algae.
Two years ago, I had an issue with my SWG where I thought the cell had quit working. I called the mfg and they told me to test for Phosphates which I did. It was over 2000. They informed me to keep the level below 600 for optimum chlorine generation. I have done this and my pool has been perfect with zero algae with a chlorine level between 2-3.

Again, I respect your opinions since I'm not an expert at chemistry, but this is what I've done this year and last and my pool has been perfect.

 

[frustratedpoolmom]

If I don't control my Phosphate level, I will get algae guaranteed.

Guaranteed? not necessarily. You're FC is too low for your CYA. If you often maintain that level, that's probably why you tend to get algae.

Phosphate removal is almost always a waste of money. If you maintain proper FC levels, it doesn't matter what your phosphate level is.

 

[chem geek]

Carl already answered this question well here at The PoolForum. You can absolutely prevent algae growth using chlorine alone, but need to maintain a Free Chlorine (FC) level appropriate to your Cyanuric Acid (CYA) level in order to have chlorine kill algae faster than it can grow. The reason is that CYA significantly reduces chlorine's strength (the "active" chlorine concentraiton, hypochlorous acid).

In an SWG pool such as yours, with a CYA of 80 ppm you need to have the FC be 4 ppm minimum to prevent algae growth. So phosphate removers can be seen the same way as algaecides. That is, IF you don't want to maintain the proper FC/CYA ratio to prevent algae growth, then that is of course your personal choice and you are free to spend money on algaecides or phosphate removers in order to do so, but you should not think that you have to do this. Usually the economics are such that it's less expensive to maintain the somewhat higher FC level and as was pointed out this has other benefits as well such as more consistent disinfection and oxidation of bather waste.

An FC level of 4 ppm with a CYA of 80 ppm has the same amount of active chlorine (hypochlorous acid) as a pool with 1.5 ppm FC and 30 ppm CYA or a pool with 0.04 ppm FC and no CYA. So don't be alarmed by the higher FC number alone since by itself that number is next to meaningless except as a measure of total chlorine capacity.

In another post on The PoolForum you mentioned the problem of constantly rising pH and frequent acid addition. By referring to Water Balance for SWGs you could manage this by lowering your TA level down to 80 ppm (or even 70 ppm at the lowest) and raising the CH somewhat and/or targeting 7.7 pH to balance the saturation index.

Richard