Confused about killing algae

May 3, 2009
105
First off let me say this is all still rather new to me. 2nd year with pool that came with house.
Having multiple issues at once, but trying to keep them separate.

Having algae growth. Have attached a pic to this post.
Not too sure what kind it is, but after reading many posts here and reading through pool school and how to shock and such...I am confused.

Chem readings as best as I can tell you since all I have are test strips. (I know I need something better...have plans to go to leslie's later on for their FAS-DPD Service Test Kit) are as follows:
pH 7.2ish (even though FC is so high I don't know if that is right)
FC 10+ (strip only goes to 10) I say + because it is dark purple before I even pull it out of the water.
TA around 80
Stabilizer seems to be zero. The color on the strip is lighter than the mark of zero on the bottle and darker is higher.

So...if my Stabilizer is this low and my FC is this high (and has been that high for over a week)
How can I be not killing algae? According to the chart here I have been at shock level for over the last week.

Other things to add... I had this happen a couple weeks ago and used yellow out and shocked each time as that stuff likes you to.
It worked, but could never get the dead stuff filtered out. The FC has not come down in over a week after that episode.
We have had a ton of rain this spring and I have let a lot of water out of the pool via backwashing.
We live in the woods more or less and tons of leaves and other tree parts end up in the pool all the time as well as critters and bugs.
Having equipment issues that puts a lot of air back into the water if that matters to this at all.

So...like I state in the subject of this thread I am confused.
If anyone can help point me in the right direction I would be grateful!
 

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That looks much more like pollen than algae. If it was algae, the shock levels of FC would have killed it.

Test strips are surprisingly imprecise. I recommend you get a top quality test kit. I recommend a kit from TF Test Kits, see the link in my signature. The Taylor K-2006 is also good. A good test kit will more than pay for it's self in saved chemicals.

If your CYA level is really around zero, you will be losing FC very quickly any time it is sunny. I suspect the test strip reading is simply wrong.
 
Well I believe it to be algae because if you touch it is is slimy and turns more green that it looks in that picture... plus it went from bright blue to horrid green over the last week.
That pic is in six inches of water on my top step...I should get one of the whole pool to show you how green it is...It isn't pollen.
 
Pollen will also feel slimy, and can be various colors. There is some chance that the photo shows dead algae, but no chance that it shows living algae.

If you do have live algae in the pool, which I doubt, you will need something better than those test strips before you can properly fight it.
 
Ok stopped by leslies and got the test kit mentioned in the reviews on this site.
FC was over 10
CC over 10 also
TA 70
pH 7.0
CYA didn't have a measure for how high it is so I'm guessing 150 or so just based on how much each 10% was and how far past the 100 it was.
So I guess that is why even though my FC is high that it isn't killing anything.

So the test strips were dead...and it turns out that was the last one anyway.

So now I have more info and will try to go back to school and see what I can come up with about lowering CYA and whatever else I can find out.

If anyone has tips I'm all ears!

Attached a pic of the pool that was all blue a couple days ago.
I can't get far enough back to get the whole pool in so look at the green in the center vs. right at the edge and the off white of the diving board.
I'm telling you...this isn't pollen making it this green since it was just blue.
 

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They actually had two with all the same testing stuff, but one had a manual and something else...a little wheel measure...didn't look that close yet.
Anyway I got the one with the book and stuff so I could get some more background on what I'm doing here and it was $52.
The bookless one was $42.
I was gonna order online, but wanted it today and there is one a couple miles from me.
So I got off cheap!
 
danbutter said:
CYA didn't have a measure for how high it is so I'm guessing 150 or so just based on how much each 10% was and how far past the 100 it was.
You can dilute your pool water 50-50 with tap water and run the CYA test again; then double the reading. You lose some accuracy when diluting but the CYA test isn't all that precise to begin with.
--paulr
 
Hi, Dan,

You will need to get rid of a lot of your CYA. The only practical way to do that is to do a partial drain and refill. There are countless threads on here of others in your same boat, but post right back if the drain-refill process is not familiar.

That is what you will need to do first.

Then you will need much, much more chlorine than you would think to clear your pool. bottles and bottles. You are correct, that's not algae.

If you are reluctant to drain and refill you will likely need twice as much chlorine as in the scenario above and probably struggle with your pool all summer
 

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PaulR said:
danbutter said:
CYA didn't have a measure for how high it is so I'm guessing 150 or so just based on how much each 10% was and how far past the 100 it was.
You can dilute your pool water 50-50 with tap water and run the CYA test again; then double the reading. You lose some accuracy when diluting but the CYA test isn't all that precise to begin with.
--paulr
Did that and came out with 140. Draining to waste as I type this.

How far down can I drain with the vinyl liner and not have issues like it collapsing in on me?
 
How far down can I drain with the vinyl liner and not have issues like it collapsing in on me?
Opinions vary. The most adventurous will say just leave at least 6" or so in the shallow end to hold the liner intact.

Others say a foot at a time.

Still others opt to drain and refill simultaneously by draining from the top of one end and filling from the bottom of the other........complex but doable if you have a high water table and are worried about the stability of your empty-ish pool.
 
Oye...wish I'd found this site last year!! Probably wouldn't have had these issues, but oh well. I'm learning.
I am using the main drain now and will likely just do a foot or so and then try the refill, rinse and repeat. :wink:

Thanks for the quick reply.
 
danbutter said:
reebok said:
nice. it's unusual for the stores to have the fas-dpd one in stock, so I was kind of wondering if you got this one instead:
http://www.lesliespool.com/browse/Home/ ... 00/I/81330

I believe you are right...that is the one I got I think.
Anyway it has all the tests I need and I have already used it so I'm happy.

Unfortunately I think you got the K-2005 equivalent. This does not have everything you need...as it does not have the FAS-DPD test which is more precise for testing chlorine, it can test up to 50ppm. You bought the DPD test and it can only test up to 5, or by dilution 10. The FAS-DPD is much easier to use because it does not use a color comparator to determine the FC, it uses a drop-count to tell you how much FC and CC you have. I would advise you to order this test seperately to supplement your kit, since you have used this one you can't return it. You can order the FAS-DPD test here, or from Taylor. :goodjob:

duraleigh said:
You are correct, that's not algae.

I think you meant to say that is algae? :wink:

Good luck with lowering the CYA. That should help improve your situation greatly. :wink: As you have probably figured out by now the issue was the overstabilized pool, not enough FC. The Yellow-Out treatment was uneccessary, and now you know the proper method, plenty of chlorine, in a properly balanced pool. :)
 
Yea, the second picture looks like algae that is half dead and half still alive. What often happens with very high CYA levels is that the chlorine is killing algae at about the same rate that the algae is growing. If the FC level is at the correct, not quite high enough level, you never kill all the algae, but the algae never completely takes over.

One of the results is that lots of dead algae accumulates in drifts on the bottom of the pool, which is what we saw in the first picture.

Once you get the CYA level down, it will be much simpler to clear up the water.
 
So how much water should I replace before shocking?
I guess the longer I wait the more effective the bleach will be due to lower CYA levels, but am I shooting myself in the foot so to speak letting the algae get worse and worse?

It is pretty bad...like birthplace of swamp thing bad already. I drained about two feet and have refilled that much now, but really don't wanna use all my bleach up now only to have to do it again in a couple days unless there is some reason to.

So, anyone have any reason to?

thanks
 

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