High Phosphates

[NelliNell]

I have extremely high phosphates and cannot get rid of them. I have tried every product my pool store offers (Phos-Free, PhosFloc and now one other one) and none have lowered my Phosphate level at all. The phosphates do drop to the bottom of the pool but I've tried having my robot vacuum them up and also vacuuming on waste and neither did the trick.

This has been going on all season and now it's mid-July. I've managed to keep the pool crystal clear all year but am really starting to get hit with bad algae. The biggest problem is that I can't get a chlorine reading b/c the Phophates are apparently taking the chlorine.

Does anyone have any suggestions or thoughts besides using one of the above Phosphate removal products? I'm literally out of options and don't know what else to do.

[aylad]

I sorta hate to tell you this, but phosphates are generally a non-issue, except for pool stores who make a LOT of money on selling people phosphate removers!! The phosphates aren't taking the chlorine--the algae is. You have been what we refer to as "pool-stored".

In theory, phosphates are algae food, so having phosphates in the pool makes it easier for algae to grow. However, if you maintain appropriate chlorine levels for your stabilizer level (CYA) in the pool, there's no algae there to consume the food!!

In order to get rid of the algae, you need to shock the pool and hold it at shock level until the chlorine is dead. Then when you let the chlorine levels drift back down, you can't let them get below what's appropriate for your CYA level, or you'll have algae again.

So...if you'll post a set of water test results (taken with a drop-based kit, no strips!!) for us to look at, we can help you get the algae cleared up and gone for the rest of the summer. You will need a drop kit to test with, though, if you don't already have one. We very highly recommend the K-2006 that you can find linked in my sig, but until you get a good kit, check your local WalMart and see if they have one of the hth 6-way drop kits. It will work for now. At the very least, pick up the cheapie OTO kit (uses red and yellow drops for pH and chlorine) and use that, because you'll have to do frequent chlorine measurements in order to kill off the algae. If you have to go with this kit, then you'll have to get the pool store to test for your CYA (but not if they're using test strips). While you're at WalMart, pick up several gallons of plain, unscented bleach.

If you'll come back and post your test results (numbers, not general phrases like "low" or "in range"), along with what chems you've put in the pool, we'll be glad to help you get it cleared up--and I promise none of it will require phosphate removers!! :)

Welcome to the forum!

[NelliNell]

Janet,
Thanks for the info and replying. I ordered the K-2006 kit and tested and got the #'s below w/ the HTH 6-way Kit.

This week I put in a bottle (32oz.) of Algaecide 30 and a large bottle (67.6oz.) of PhosFree. It has rained today so that may have an effect on these results. My pool is roughly 16x32 w/ 8ft. deep end. I want to say I've been told it's about 20,000 gallons.

Cl/Br: .5 if not 0 (It's pretty clear)
pH: 7.8
Alkalinity: It took 13 drops so 130 I guess is the # you're looking for?
Hardness: Color was more purple. I did the test regardless and I'd say it turned blue by about drop 10-11 but it was difficult to tell the color change
CYA: 60

Thanks, Jeff

[Watermom]

With a CYA of 60, you have to keep your chlorine between 5-10ppm ALL the time or you get algae. That's what is happening in your pool. To get rid of it, you need to shock the pool up to 20ppm and keep the chlorine at that high level until you can go from sundown one evening until within two hours the next morning without losing more than 1ppm of chlorine overnight. We then usually suggest keeping the chlorine high for one additional day and then letting it drift down.

In a 20K gallon pool, each gallon (4 quarts) of 6% bleach will add 3ppm if chlorine. Use that as a reference to help you figure out doses of bleach to add. Each time you test, add enough bleach to get back to 20. The more consistently you can keep it there, the faster it will clear up. Un

Until you get the K-2006, you can force your kit to read higher with dilution. Not super accurate, but better than nothing.

Info here: Testing Without a Good Kit (http://poolsolutions.com/gd/how-to-test-your-pool-without-a-good-testkit.html )

Don't add anything else right now but bleach. If your pH goes to 8 or higher, you'll want to use some muriatic acid to lower it. But, before doing so, please read the link in Jan's sig above about using it safely.

Hope this helps!

[NelliNell]

One more question before I add the bleach. Should I add it immediately this morning or wait until late today? The pool store always told me it was best to add it when the sun is going down or not as strong and your post references sundown but wasn't sure if I just need to get something in now since I have no chlorine reading?

Thanks for your help!
Jeff

[aylad]

With a zero chlorine, you need to get bleach in it today--NOW! :)

If the water is green, go ahead and shock the pool per Watermom's instructions. You'll need to test as often as you can during the day, and add whatever amount of bleach you need to get back up to the shock level. The more consistent you are about keeping it at that high level, the quicker the pool will clear.

The reference to sundown that Watermom made was for testing, after the pool has cleared, to make sure all the algae is gone. If you test one night and again the next morning without having added any more chlorine to the pool, and don't lose any in that time, then you're finished shocking and can let the chlorine drift back down. But while you still have green water, you just need to test as often as possible and focus on maintaining that shock level of 20 ppm.

Janet

[NelliNell]

That's the thing, the water is crystal clear

[Watermom]

It may be clear now, but if you let your chlorine drop to 0 with a CYA reading of 60, then you probably have something starting in there that hasn't "bloomed" yet. My advice is the same. Go ahead and shock the pool. It may be that doing so one time will be all that you need and you'll find that you don't lose more than 1ppm of chlorine overnight. If that is the case, then you'll be good to go as long as you don't let the chlorine drop again. But, my opinion is that it is better to go ahead and shock a pool that looks clear rather than chance it and end up with a green pool.

[NelliNell]

Can I assume it isn't safe to go in the pool until I'm done with this process and am able to let the chlorine drop to normal levels?

[aylad]

I wouldn't have a problem with going in the pool, but you don't want to wear brand new suits while the pool is at shock level. As long as the water is clear and there is "some" chlorine in the pool, I wouldn't have a problem swimming in it.

[PoolDoc]

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