green pool

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Use the poolcalculator.com to determine as well as you can how much chlorine to add to stay near the max FC your strip can read (your actual CYA level determines what your real shock FC level should be).

Give you filter a good cleaning and then you will know the clean pressure for next time.
 
Well, I've been struggling with the algae problem for about a week.
Our pool is now blue in colour although cloudy. When I brush the sides and bottom of the pool there is a faint greenish film that comes up.
I have been maintaining our chlorine for the most part >10 (previously only had the dip sticks). We do have a salt pool but it hasn't worked for most of the summer (guy coming tomorrow to fix!!!).

I finally got the test kit to do a more thorough test. Here are my results so would appreciate help and feedback.
FC 6 ppm
CC 0.5 ppm
pH 7.6 - after doing the pH is asked about the acid demand and base demand Is this something you usually test?
TA 150 - is the colour more pinkish rather than red
Ca Hardness - yes ?how blue should the colour be?
CYA 50

Any advice as to where to go from here?
Thanks
 
Which test kit did you get? (assuming K-2006 based on your pH comment since the TF-100 does not have the demand reagents ... and thus most of us do not do those tests).

Lower the pH in the lower 7s and then start following the shock process correctly. With a CYA of 50ppm, you should keep your FC at 20ppm until you pass the 3 tests to stop. Leave the SWG off and finish the process with bleach.

You can worry about the TA and CH later.

More test details are available here:
extended-test-kit-directions-t25081.html
 
I vacuumed the pool on the weekend and then backwashed; my pressure was at 10 afterwards.

I bought the K-2006

I will put in a value of pH in the calculator at ? 7.2 to see how much acid I need to add
 
How much is the pH affected by high chlorine levels? My pH was 7.6; someone from the site recommended adding muric acid to lower the pH to 7.2 to improve the chlorine effect and help clear up the cloudiness. I added the recommended dose this morning and 6 hours later the pH if anything was slightly higher. So my qyestion is how accurate is the pH when my chlorine level is at 14?
 
BStaveley said:
How much is the pH affected by high chlorine levels? My pH was 7.6; someone from the site recommended adding muric acid to lower the pH to 7.2 to improve the chlorine effect and help clear up the cloudiness. I added the recommended dose this morning and 6 hours later the pH if anything was slightly higher. So my qyestion is how accurate is the pH when my chlorine level is at 14?
Click to expand...

Here is a pretty good, fairly recent discussion pertaining to your question
 
Thanks I thought I had read that somewhere. I did check my pH prior to beginning the shocking process. At the time I only had the dip sticks but it looked like it was an okay level so I guess I won't worry about it until I meet the 3 criteria for algae begone
 
How old is the sand in the filter? If it has been more than 3-5 years since you changed the sand, it may be time to change it. The older it gets, the less efficient.

How big is the pool? Liquid Chlorine is the fastest acting way to treat algae in my experience. If you are shocking to a level reading 10ppm, the pH results should not be trusted as the high chlorine will mask/alter your results. Wait until the chlorine comes down to get an accurate pH reading. High pH can also cause a green tint to the water. Salt generating systems often run higher pH because the chlorine that is generated has a very high pH. of about 8.5. To control the impact of the high pH in a salt pool an alkalinity of 180 should be reduced until it is in the lower acceptable range of 80-100. As the pH increases the chlorine efficiency goes down.

We recommend that a pool is backwashed when the pressure increases by 5-7ppm. How often this happens depends on the age of your filter media, if you have used the system to vacuum, and your environment around your pool like a lot of trees and debris. I often backwash during and after vacuuming my pool, as well as when I notice the jets are not as powerful as they usually are. If the filter needs to be backwashed, that can cause the filter to be inefficient, and it can take longer to remedy an algae issue.
 
TFP does not recommend changing sand. Cleaning, perhaps yearly, but not changing.

Also the filter backwash rule of thumb is after a 25% rise from baseline pressure - not the static 5-7 lb rise used by many in the industry.

-sent with Tapatalk 2
 

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TFP also recommends backwashing/cleaning the filter when the pressure goes up 20-25% of the clean pressure.

Additionally, I am pretty sure you description of the chlorine generated by the SWG is incorrect. It is the aeration that results in the pH going up and not the ph of the chlorine (which is a gas).
 
I know there are different schools of thought on sand changes. I know what has worked time after time based on first hand experience. If not changing the sand is the theory you'd prefer to follow, that's great.

Salt water chlorination is a process that uses dissolved salt as a store for the chlorination system. The chlorinator uses electrolysis to break down the salt (NaCl). The resulting chemical reaction eventually produces hypochlorous acid (HCIO), and sodium hypochlorite (NaClO), which are the sanitizing agents already commonly used in swimming pools.

Hypochlorous acid is a weak acid with the chemical formula HClO. It forms when chlorine dissolves in water. It cannot be isolated in pure form due to rapid equilibration with its precursor. HClO is an oxidizer, and as its sodium salt sodium hypochlorite, (NaClO), or its calcium salt calcium hypochlorite, (Ca(CIO)2) is used as a bleach, a deodorant, and a disinfectant.

Sodium hypochlorite is a chemical compound with the formula NaClO. Sodium hypochlorite solution, commonly known as bleach, is frequently used as a disinfectant or a bleaching agent.
 
The pool was new last August so I would hope that the sand filter is still doing its job.
The salt chlorine generator has not worked all summer, new parts were put in today and it seems to be working now (just in time to shut the pool down)
THe FC tonight was 18.6 so will probably leave it at that overnight and see what it's reading in the morning.
My clean filter pressure seems to be around 10. I didn't check it today but yesterday it seemed to be holding at 10 after vacuuming on Saturday and backwashing.
I understand the pH reading not being accurate due to the high chlorine but what about the TA. Is the TA affected by the chlorine?
 
The TA test should be fine at high levels of FC ... but there is not point to be checking it. Just focus on the shock process and when complete and the FC drops ... then worry about the rest.
 
So this morning FC held stable overnight if not slightly higher? last night FC was 18 this morning it's 20
CC 1.0
Water still cloudy although I think slightly better than yesterday.
I will brush the pool, any other thoughts as to what I should do?
 
Retest. FC can not go up w/o added chlorine. Maybe your night measurement was too soon after adding chlorine? Try brushing the pool while waiting to measure to help mix things faster.

Also be sure to keep your method as consistent as possible. You may want to check the water at night a couple of times to be sure you are getting repeatable results.

Lastly keep shocking, cc is too high, and water is not clear. Still need to pass those criteria.


- Sent using Tapatalk
 
Ok wondering if the difference from last night to today in the FC was because last night I did the 25 ml sample and today did the 10 ml sample?

So because my FC is okay ? I don't need to add more chlorine just keep an eye on the levels, brush daily and maybe vacuum to waste in the next day or two?
 
BStaveley said:
Ok wondering if the difference from last night to today in the FC was because last night I did the 25 ml sample and today did the 10 ml sample?

So because my FC is okay ? I don't need to add more chlorine just keep an eye on the levels, brush daily and maybe vacuum to waste in the next day or two?
Click to expand...

Your use of 25ml vs. 10ml could impact the test but in theory it should not.

FC will drop in the sun, test again in a few hours if possible.



- Sent using Tapatalk
 
Changing sand every "3-5 years" is positively not necessary and not recommended by TFP. Speaking from experience of helping care for my father's concrete pool for 27 years before dozing it in (his choice). In those 27 yrs, the sand was changed once, and that was only because of replacing damaged laterals, so what the heck, we put in new. His pool was perfectly cystal clear all those years. Sand is already millions of years old. A few years in a filter isn't going to "make it old" and "less efficient."
 

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