Need Help with green algea

Brentr

Gold Supporter
LifeTime Supporter
Oct 18, 2009
3,635
Jacksonville, FL
Pool Size
6000
Surface
Plaster
Chlorine
Salt Water Generator
SWG Type
Hayward Aqua Rite (T-15)
So I have mustard algea in my pool for the last week. Here are the chems
FC- 5
TC - 10
CC - 5
PH - 7.5
TA - 130
TH - 250
CYA - 50

The pool is approx 5775 gals. The water is clear. SWG is on target at 3400. I am assuming that I need to shock it and would like to know how much liquid chlorine I need to add. I have tried to use the pool calculator however I must be doing something wrong. I would appreciate some suggestions.

Thanks in advance
 
1.9 96 ounce jugs or 1 large 182 oz jug will get you to 20, which is your shock level. But given your high CC (did you use any MPS?) that will rapidly be consumed, so I'd buy at least 10 small jugs or 5 large jugs to play it safe.
 
Thanks, I plan on using the Bleach 6% from the store. I will buy 5 gals (46oz) and put it in today. Is that what you are suggesting? Also forgive my education level but I do not know what MPS stand for?
Thank you for your direction and support
 
MPS is a pool store product they may have sold you to help clear up your algae. It will be called something else but under ingredients will say "monosodium persulfate". That would account for your high level of CC's which is unusual.

Nevertheless, chlorine is what will clear your pool.

If your water is clear, and you have algae present on the sides/floor of your pool, you should be brushing that algae to expose it to the chlorine. I'm sure it will cloud your water when you do but it is difficult to kill if you leave it clinging to the sides/floor.

Brush a couple of times each day, keep your FC levels at shock value, and run your pump 24/7....your pool will clear.
 
MPS is non-chlorine shock with the ingredient "potassium monopersulfate" or "potassium peroxymonosulfate". It interferes with the Combined Chlorine (CC) test. As was stated above, raise the Free Chlorine (FC) high to shock level using chlorinating liquid or bleach and maintain it. If it's truly yellow/mustard algae, then you may need to raise the FC as high as 30 ppm (given your 50 ppm CYA level) to kill it thoroughly. If it's just green algae, then 20 ppm FC should be sufficient.
 
Hi Guys thank you for your help. I put 2 jugs of bleach 6% (182oz each) and brushed a bunch of times. I checked the ph and chlorine about 1hr later and both went off the chart. I guess ph will rise after shocking.
1. Can you tell me when would be a reasonable time to check chemistry after shocking?
2. Also I am thinking of adding borax to my pool as I read that it will help stablize my ph and chlorine. My pool is 2 1/2 mths old. How do I test for borax levels? What is a good level to shoot for? I ordered the t-100 test kit yesterday.
Thanks you for your direction and support
 
Brentr said:
Hi Guys thank you for your help. I put 2 jugs of bleach 6% (182oz each) and brushed a bunch of times. I checked the ph and chlorine about 1hr later and both went off the chart. I guess ph will rise after shocking.
1. Can you tell me when would be a reasonable time to check chemistry after shocking?
2. Also I am thinking of adding borax to my pool as I read that it will help stablize my ph and chlorine. My pool is 2 1/2 mths old. How do I test for borax levels? What is a good level to shoot for? I ordered the t-100 test kit yesterday.
Thanks you for your direction and support

Yes, anytime you have a FC higher than 10, your PH will read high. So we recommend testing and adjusting PH if necessary before beginning a shock process.

We recommend 30-60 minutes after adding bleach to check for FC/CC. Make sure you leave the pump running 24/7 while shocking.

There are Borate Test strips available for purchase - email Dave (Duraleigh) at TFtestkits and see if you can add it to your order, since he probably won't ship it out till Monday. Read this article for information on Borates:
http://www.troublefreepool.com/so-you-want-to-add-borates-to-your-pool-why-and-how-t4921.html

Borates are totally optional and honestly, I recommend you "get to know your pool" a bit longer before you attempt adding borates.

Remember PH will rise rapidly at first and continue to drift up for 1 year while the plaster cures. :wink:
 
Okay, I just received my tf-100 and it took 3 days. I was so excited that I had to take some readings. The water cleared up however some mustard dust has settled on the floor of the pool. Here are the readings.
FC - 31.5
CC - 8
TC - 38.5
PH - 7.5
TA - 100
CH - 680
CYA - 80
Temp 80
SWG says 3200

I guess that I put too much bleach in. What are your thoughts? I have to add some water to the pool as we have been very dry.

Thank you for your direction and support
 

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I guess that I put too much bleach in. What are your thoughts?

BBB is testing accurately and applying your dosages accurately so you get predictable results. Dose carefully. :-D

What you see on the bottom of your pool floor is dead algae. You need to continue the shock process (by holding the FC up around 20) until your CC's drop to .5ppm or less.

Please read "How to shock your pool" up in Pool School. It is a process that will take a few days.

Run your filter 24/7 and vauccum as much of the dead junk up as you can.

It'll take a while but your pool will soon be crystal clear.
 
When should I do more tests? The FC is 31.5 and the CC is 8.
If your SWG is shut off (it should be), the FC will come down into the 20 somethings pretty soon. I'd monitor it closely and test daily, being prepared to add more Clorox once it gets down to 20ppm
 
Brentr said:
When should I do more tests? The FC is 31.5 and the CC is 8.
Shocking is a continual process that is begun by quickly raising the chlorine level, then keeping it at that high level until you're finished. You may need to test and add chlorine as often as once every hour or two during the first day then frequently (twice a day or more) thereafter. See the excerpt "Shocking" below.

Note, however, that the recommended 20-30 ppm shock level was based on two assumptions that are no longer valid: 1) current CYA level is 80 (not 50, as was believed); and 2) type of algae identified as "mustard", not green. If this is correct, you may want to drain some pool water in order to reduce the CYA level before you commence further shocking.

The recommended chlorine shock level is 46 ppm (not 30) for mustard algae growing in pool water with a CYA level of 80 ppm. See Chorine-CYA Chart


Shocking:
  • 1. Measure the FC level
    2. Add enough chlorine to bring FC up to shock level
    3. Repeat steps 1 and 2 as frequently as practical, as often as once per hour, and not less than twice a day, until:
    [list:3dnus956]a. CC is 0.5 or lower;
    b. An overnight FC loss test shows a loss of 1.0 ppm or less;
    c. And, if you don't have a FAS-DPD test kit, the water is clear.
[/list:u:3dnus956]

 
I would confirm the results of your CYA test. It's pretty subjective and easy enough to get a little incorrect. What CYA test did you use to get 50ppm the first time? similar turbidity test or test strips?

I would also suggest you do not likely have mustard algae. It is probably the most common mis-diagnosis of pool problems. The extra chlorine to fight mustard algae probably wont hurt a thing but you may not need to use it. What does your water look like currently?
 
With a CYA of 80 your shock value is higher. So I agree with Dave, confirm the differences....

A CYA of 80 is in range for an SWG. So you are sort of in a rock and a hard place, if it is really 80. Because you do have to shock very high in that case. On the other hand, your CH is very high, so maybe a partial drain and refill would be a good idea, and then you can always increase the CYA back to 70 later.... :?

I don't mean to contradict anyone but it's okay to run your SWG to help maintain shock level if you want. :wink:

You should not use the swg to try to reach shock level, but once you are there, it can be turned on to help maintain. The high CC is alarming, but basically you need to maintain shock level testing and adding bleach if necessary very often until the CC is down to .5 or less and the FC is holding. The SWG must be turned off to correctly perform the overnight loss test.

If you see that crud on the bottom of the pool with your chlorine that high, what you are seeing is not Mustard Algae, just dead algae.

True mustard algae vanishes at shock level only to return when the levels drop. It's not the dusty cruddy after affects and people often confuse it. I agree with Dave, that's its probably not what you are seeing.
 
I put in another jug of bleach and will perform a chem test later this evening. The mustard stuff on the bottom of the pool may very well dead. The CYA test of 50 original was results from Leslie's pool test and it was done on 10/24/09 and the original CH original of 210 was from Leslie's. If I have to perform these tests I will be running out of test chemicals and will have to order them by the gallon :-D
 
Okay here are my tests
FC - 40
CC - 0
TC - 40
PH - 7.2
T/A - 100
CH - 1200 ( stopped at 60 drops using the quantities in brackets )
CYA - 60
Pool temp 71deg
SWG 3300

I must be doing something wrong or is it possible to have a batch of bad reagents. I know that my CH should be much lower because when tested at Leslies pool store on 10-24 09 it was 210 and on 10-03-09 it was 240. I could never get it to change from pink to blue. It turns clear after about 20 drops. Can anyone make some suggestions? I checked it twice this am and I am using up a lot or R-00012 reagent.
 
Brentr said:
Okay here are my tests
FC - 40
CC - 0
TC - 40
PH - 7.2
T/A - 100
CH - 1200 ( stopped at 60 drops using the quantities in brackets )
CYA - 60
Pool temp 71deg
SWG 3300

I must be doing something wrong or is it possible to have a batch of bad reagents. I know that my CH should be much lower because when tested at Leslies pool store on 10-24 09 it was 210 and on 10-03-09 it was 240. I could never get it to change from pink to blue. It turns clear after about 20 drops. Can anyone make some suggestions? I checked it twice this am and I am using up a lot or R-00012 reagent.

I forgot to say that the water is crystal clear and there is no more crud or mustard colored stuff on the bottom of my pool. I also confirmed using a test strip and it says that my CH is Around 250. The only thing that I have added is 5 bottles of bleach and muratic acid to keep PH down. Do you think I have a bad batch of chemicals? I only received the kit last week :(
 
I doubt that you have bad reagents. The CH test requires lots of patience. Are you swirling plenty between drops?

Here are the instructions: Are you following them exactly?
1) Rinse and fill sample tube to 25ml mark.
2) Add 20 drops R-0010; swirl to mix.
3) Add 5 drops R-0011L; swirl 20-30 seconds to mix. Solution turns red to indicate calcium is present.
4) Add R-0012 one drop at a time, swirling continuously, 20-30 sec between drops. Repeat until color changes to blue (and stops changing).
5) The last drop that caused a change is the drop count. Multiply #drops by 10 to get CH.

Double check your bottles and make sure you're using 0010, 0011L & 0012 in the proper sequence. There have been some people that didn't get the exact colors indicated but the test is still valid if you drop until the color stops changing.
 

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