A few questions

May 26, 2008
18
#1
Im new to the BBB method and a fairly new pool owner and have a few questions.I have a 21x 41 dough boy oval pool.we changed the liner about a month ago.The water is clear and looks reallly good.
1. How much bleech should I be using (a gallon a day)?once my lvls are consistent?
2.What should my backwash pressure be?(mine been running around 18,should it be high or low?)
3.What would be the shock lvl?and how many gallons of bleech should it take?
 

frustratedpoolmom

TFP Expert
LifeTime Supporter
In The Industry
May 20, 2007
12,177
SWSuburban Chicago, IL
#2
Welcome to TFP!

It's a helpful idea if you post a complete set of test results, which show your pool's total chlorine, PH, TA, CH, and especially CYA, because these numbers help us help you. Also, include in your profile/signature the type of equipment you have.

Read the "stickies"
http://www.troublefreepool.com/sticky.php

That will tell you a lot.

If you still have questions, post your test results and your pool info and we should be able to help you better....:)
 

Titanium

LifeTime Supporter
Jun 26, 2007
441
SF Bay Area
#3
tosborn55,

Welcome to TFP.

For your questions 1 & 3, we will need a full set of testing numbers. This sticky will tell you what test results we need and which kind of test kit is needed. http://www.troublefreepool.com/sticky.php?s=3662

For question 2, we will need to know more about your equipment. I.e. filter pump hp, type of filter, etc. The above sticky will give you guidelines on what kind of info we need here also.

We will be waiting to help when you get back.

Titanium
 

Matt

Well-known member
Jun 5, 2008
126
#5
You have to be adaptive in the way you add stuff to your pool. In other words, test and base the amount of bleach (or other things) you add on the results of the test.

The amount of each chemical I add daily varies a lot. I don't always know why. Sun and bather load affect things, as do organics. The basic point though is that nothing substitutes for testing and basing your decisions on that. Once you test, and you know your current level and target levels, you can use Jason's calculator to figure out how much to put in of each chemical.
 
May 26, 2008
18
#6
Ok i got the results...
cya 27
fc 0
ph 7.9
alk 122
hardness 238
I have a 21x41 oval with a sand filter,2hp motor ,above ground dough boy.it seems the cya is a bit low,but im suspecing I have a algae problem.So im guessing shock it,but how much bleech to shock it?
 

Rangeball

Well-known member
May 25, 2007
785
#7
With a 0 FC reading, you need bleach, cause if you don't have an algae problem you probably will, soon.

How much bleach depends on how many gallons your pool holds, your CYA ppm level and the type of bleach you use.

I used Jason's calculator and your pool dimensions and assumed a 4.5' depth which puts your pool volume at 25,800 gallons.

Based on your CYA level of 27 (this is fine for now if you feel it is an accurate reading), your target FC residual is 3.5 ppm, with a minimum of 2.2 ppm. Shocking requires 12.2 ppm.

Assuming you use 6% bleach, from a 0 reading it would take 187 ounces to get to 3.5 ppm (2 .75 gal jugs or 1.5 gal jugs), and 653 oz for 12.2 ppm (7 .75 gal jugs or 5 gal jugs).

If you shock, do it tonight, after sundown. After the water has circulated, get a FC reading. Then again in the morning to see how much chlorine was consumed overnight.

Your PH is also a bit high which will reduce the chlorine's effectiveness. You need to add 66oz of 31.45% strength muriatic acid to lower it to 7.2.
 

frustratedpoolmom

TFP Expert
LifeTime Supporter
In The Industry
May 20, 2007
12,177
SWSuburban Chicago, IL
#8
Have you read the sticky's and seen the pool calculator?

http://www.poolcalculator.com/

I plugged in your numbers (try it yourself, and get the hang of it)

and it shows with your CYA (about 30) that your shock level is 12ppm. Since your current FC is 0, you should add 6 jugs of bleach (96oz siz). that will bring you up to 12 ppm but you will need to add some each night to keep you at 12pmm so retest and then punch in the caclulator to see how much to add each night. That's why you need a good test kit, to tell you how much FC you have in your pool, so you know how much to add. You DON'T want to add 6 jugs each night without knowing what's leftover from the night before, if any.

To lower your ph, it said to ad 31oz of muratic acid.

To increase your CYA to 40, which I recommend, ad 40 oz of stabilizer.

Hope this helps.
 

frustratedpoolmom

TFP Expert
LifeTime Supporter
In The Industry
May 20, 2007
12,177
SWSuburban Chicago, IL
#9
Rangeball and I had the same thoughts, slightly different numbers but the gist is the same.

Test, enter your numbers in the calculator and make your adjustments.

It's going to be fine, just take your time and if your confused, just post and someone should be there to help.
 

Rangeball

Well-known member
May 25, 2007
785
#10
frustratedpoolmom said:
Rangeball and I had the same thoughts, slightly different numbers but the gist is the same.
Probably explained entirely by differences in estimated pool volume and how we rounded the results :)

I showed more acid to get her PH to 7.2, and I assume you just calculated enough to get her to mid-range. I suggested a bit lower as her TA is still slightly high, and she should get some PH drift back up.