Algae in the pool

pjpool2010

Active member
Jun 7, 2010
42
Hi,

I have a Vinyl inground pool (size 20x40, 33,000 gallon) and had not opened last year since we were out of town. Now that I opened it, I see the pool water is green.

I went to local Leslies pool store and got water checked. Here is the result:

Ph: 7.5
Chlorine (DPD Test): 1.2
Alk: 100

I have shocked the pool twice with 4lbs of "Power Powder Pro" each time by mixing it in water before pouring it into the vinyl pool. (Per pool store, it strong and hard on vinyl)

Based on Leslies pool's suggestion, I bought this weekend "Chor Brite" 40lb bucket for $134 to shock the pool futher to get rid of Algae. I haven't opened the new box yet. Is there a cheaper alternative for it?

Experts, please recommend me on how to get rid of Algae and what type of Chlorine should I use for my vinyl pool. I would appreciate your input.

Thanks,
 

dmanb2b

TFP Expert
LifeTime Supporter
Apr 4, 2009
3,734
NY
Welcome to TFP :goodjob:

Yes there is...ditch the chlorbrite. Order a good test kit such as the TF100XL from tftestkits.net or the taylor k2006. (The TF100XL is specifically designed for folks looking to turn their swamp into an Oasis (Covered in Pool School) While waiting for the testkit, please read pool school thouroughly (button on upper right of this page). Once you can post a full set of water results (FC, CC, PH, TA, CH, CYA), we can give you assistance and what will likely be followed bylots of liquid chlorine addition to your water(either the 12% pool store stuff or 6% bleach from the ) That bucket of shock they sold you, will overstabilize your pool water.

For now...it sound like the alage is winning the battle and you are not adding enough chlorine to obtain shock level. As explained in Pool School..Shocking is a process of adding enough chlorine to superchlorinate your pool water. What pool stores sell as "shock" is just another source of chlorine :goodjob:
 

pjpool2010

Active member
Jun 7, 2010
42
Thanks for quick response. I currently own Pool solutions PS233 test kit. I will try to order the suggested test soon. Here are my current test result values:

FC - 1.2
CC - do not know
PH - 7.5
TA - 140
CH -
CYA - 0

Should I go ahead and buy liquid Chlorine from pool store. Where do I buy the bleach, homedepot/walmart? Should I use the household Clorex liquid? Any suggestion on the quantity to be used and the process would greatly be useful.

Thanks!
 

svenpup

LifeTime Supporter
Nov 18, 2009
835
Sacramento, CA
Given your CYA = 0, you could use some of the chlor brite, but if you use it all you will have over-stabilized water (CYA ~75). You should probably return it if you can.

You will need you get some CYA in there somehow (30-50ppm) so you will have to go to the pool store for that, if you decide to return the chlor brite.

Bleach and liquid shock are the same ingredient (Sodium hypochlorite) in different concentrations. It doesn't matter if you get it from the pool store (10-12%) or the grocery store (6%) except you will have to lug more jugs of the less concentrated stuff.
 

PaulR

LifeTime Supporter
Jan 11, 2009
1,966
Cupertino, CA
If Leslie's won't let you return the dichlor, you can use about half of it and your CYA will end up in about the right place.

As svenpup says, bleach and liquid chlorine are the same stuff at different strengths; the only real considerations are cost, jug count, and in some cases a pool store uses returnable or refillable jugs.
--paulr
 

pjpool2010

Active member
Jun 7, 2010
42
Hi,
I new to the forum and still learning on chemical balance. Water now looks light green/greyish from dark green. Lesile wouldn't take the "Chor Brite" 40lb ($126) bucket back. I guess, I have to use it for now.

I had water tested again today and here is the result, please suggest on how I can get sparkling pool by weekend!

Saturation Index: 0.4
CYA: 30
pH: 7.8
TC: 5
FC: 0
TA: 145
TDS: 500
Total Hardness: 222
Copper: 0
Iron: 0

How much more shock should I put in pool? I currently have Chor Brite" 40lb bucket.

Thanks in advance!
 

frustratedpoolmom

TFP Expert
LifeTime Supporter
In The Industry
May 20, 2007
12,179
SWSuburban Chicago, IL
You need to learn how to use the pool calculator to figure that out for you.

You can use the Dichlor about two more times and then your CYA will be at the top of the ideal range...and you'll want to switch to liquid chlorine...

So punch in the numbers, and post back here what dosage you come up with and we can verify if you are correct before you add it.

Weekend? :shock:

Read How to Shock your Pool:
http://www.troublefreepool.com/pool-school/shocking_your_pool
 

pjpool2010

Active member
Jun 7, 2010
42
Keyed in the the number to the calculator and suggestion it provided is:

Add
33oz or 2lbs of dichlor (i will use chlor brite from Leslies)

Is this correct? please suggest
 

pjpool2010

Active member
Jun 7, 2010
42
I entered the following in Now field:

FC: 0 (target 4)
pH:7.8 (target 7.2
TA: 145 (target 100)
CH: 222 (Calcium)
CYA: 30
Size 34,000 gallon

Pressed calculate button. I picked from list box dichlor

What did I do wrong.
 

frustratedpoolmom

TFP Expert
LifeTime Supporter
In The Industry
May 20, 2007
12,179
SWSuburban Chicago, IL
You're not 'wrong' just trying to fix it all at once. I suggest you focus on the Dichlor (which by the way happens to lower PH/TA)

Enter FC of 0 and a shock level of 12 for your target - hit calculate and add that amount of Dichlor. Predissolve it in a bucket and pour it in front of the return, tonight if you can. Then tomorrow morning, test the FC again, enter the result as your "now" and 16 as your target. 16 will be your new shock level, because tonights Dichlor addition will put your CYA level at about 40.

Does this make sense? :)
 

poolgirl22

Platinum Supporter
LifeTime Supporter
Apr 14, 2010
595
Stephens City, VA
pjpool-
I hope I didn't come across as short by asking that question. If I did, I apologize. I was just trying to identify where the missing link was. Now I think you'll be on the right track. :goodjob:
 

pjpool2010

Active member
Jun 7, 2010
42
I am newbie and slowly it's making sense. :)

Based on the FC=12 target, I have to add 6lbs of dichlor. I will add it overnight and follow the instructions for AM.

Thanks again!
 

pjpool2010

Active member
Jun 7, 2010
42
Hi,

After the overnight shock, the FC level currently is 1.2 and pH is 6.8. Per the calculator and your prior input, do I need to put 7lb 6oz shock. Correct?

What should I do with low pH?

Thanks!
 

poolgirl22

Platinum Supporter
LifeTime Supporter
Apr 14, 2010
595
Stephens City, VA
Your shock calculation is accurate.
Now, keep in mind going forward, you should not add any more dichlor after this next addition. You will be raising your FC by 15 and your CYA by 14 with this addition, so you'll be around 55 for a CYA. That is my level and it's a high as I ever want to go because shocking is no fun at higher levels. You'll want to switch to liquid. Save the dichlor for down the road if you should need to add CYA again.

But wait for FPM to or another person to chime in here on the Ph situation...the dichlor you added has a lowering effect on Ph...and I THINK you'd want to raise that back up before adding more dichlor which will lower it again. I don't have much experience with raising Ph in relation to shocking as I'm historically one who has to lower it. Mine always shows super high above 10 ppm of FC so I have to ignore it completely when shocking.

You're doing great.
 

svenpup

LifeTime Supporter
Nov 18, 2009
835
Sacramento, CA
Borax is the TFP version of pH up. Use the pool calculator to determine how much you need to get up to 7.3 or so. Normally you want your pH a little higher, but shocking is more effective at lower pH.

Are we keeping track of how much CYA is accumulating? I didn't go back though all the posts, but it looks like a lot of dichlor.
 

poolgirl22

Platinum Supporter
LifeTime Supporter
Apr 14, 2010
595
Stephens City, VA
svenpup said:
Borax is the TFP version of pH up. Use the pool calculator to determine how much you need to get up to 7.3 or so. Normally you want your pH a little higher, but shocking is more effective at lower pH.

Are we keeping track of how much CYA is accumulating? I didn't go back though all the posts, but it looks like a lot of dichlor.
That's what I was thinking...thanks svenpup. I thought because she was at a lower FC reading that adjusting was fine. Wait for it to circulate awile. Then add the dichlor.

Yes, FPM had her squared away on the accumulating CYA and I also reiterated above that she should stop using Dichlor now and switch to liquid after this next addition. OP had large bucket that Leslies wouldn't take back...typical... :roll:

pjpool--I came up with 28 lbs of borax (5.9 boxes) to raise PH from 6.8 to 7.3) so you'll want to go to the store and get 12 boxes (its a couple dollars a box at wally) because this next round of dichlor is going to likely lower your ph again from 7.3 to around 6.8. (I get this from the effects of adding chemicals section of the pool calc at the bottom. Enter the dichlor ounces you are planning to add and it tells you the effects.) Enter the info in pool calc and see how it works. :-D

While you're there, buy plain Great Value Bleach in the 182 oz size, around 2.50. Start with 6 jugs. You may have to go back for more but 12 boxes of borax and 6 jugs of bleach should be enough to fill up your cart.

Edit: If you don't want to have to go through the expense and hassle of raising your ph again after the next dichlor addition AND ending up at a higher CYA level (40 is fine, but if you do the next dichlor you'll be around 55) you can choose not use the dichlor this time, save it for down the road, and just buy the 6 boxes of borax you need to raise it now and invest in more bleach. Your shock level will then stay at 16 rather than going to 22, you likely won't have much ph adjustment to do, and you'll be keeping things at an easier shock level. I'd love to be at 40, but FPM didn't catch me quick enough... :wink:

In terms of bleach...the difference between bringing FC from 0 to 16 vs. 0 to 22 is....8 gallons vs. 12 gallons...you'll be saving yourself money if you stop the dichlor now and switch to bleach
 

svenpup

LifeTime Supporter
Nov 18, 2009
835
Sacramento, CA
I just looked back at your TA of 145. Do you have any way to aerate? If you aerate through this process it will help keep your pH up and you wont have to use as much borax. You are sort of wasting your low pH. Later, when you want to get your TA down you will be adding acid which you are getting now for free.

Read pool-school/lowering%20total%20alkalinity
 

poolgirl22

Platinum Supporter
LifeTime Supporter
Apr 14, 2010
595
Stephens City, VA
Good thinking svenpup.

I'm so concerned about the dichlor and controlling the CYA and shocking thing I wasn't looking past that. Plus, again, low PH has not been a focus for me personally so that trick didn't come to mind.. :goodjob:

(psst...I'm really hoping the OP just stops using dichlor right now and gets the ph up ASAP so she can get to shocking with bleach... :wave: ) :mrgreen:
 

pjpool2010

Active member
Jun 7, 2010
42
We added more dichlor based on earlier comments before reading through other posts. :-(
We do not aerate capability.
I will check the readings when I get home. Looks like it rained earlier today. Not sure of the rain affect on pH.
Do I get borax and Great Value Bleach in target or walmart/samsclub? Or there are other stores that sell cheaper and larger quantity.
I do have national pool near my home that sell liquid chlorine. I am guessing it will be pricey compared to generic brands. Please suggest.
 

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