Hello
Last year we went for a long break back to the UK leaving precise instructions on how to keep the pool and water clean. When we arrived back the water was clean and all looked good until I turned on the circulation pump/filter. I soon realised that the person who was cleaning the pool had not backwashed the filter and dirty water was entering the pool via the filter.
After many attempts at backwashing and refilling the pool I got the water to an acceptable state of cleanliness albeit not sparkling like it used to be but every time I topped up the Chlorine level the pool water went cloudy. I have done a full test today with the following results: -
FC 5, CC 3.5, TC 8.5, pH 7.8 ( I have not had to add any Soda Ash for a long time?) T/A 100, CH 300, CYA 30

The sand filter has been operating for 5 years, is it possible the sand in the filter needs changing?
Could the cloudy water be dust particles suspended in the water?
Any advice would be gratefully received as long as it is not empty and refill the pool as that would be extremely expensive, water is not cheap here.
Best wishes to all
Mike

With your CC at 3.5, you are likely fighting an algae bloom. Shock the pool until you pass the overnight chlorine loss test. You will likely find dead organics on the pool floor that will need to be vacuumed out after. I suggest, if possible, using the waste setting to get the majority of it out. Don't try to be perfect in this setting or you will blow out more water than you need.

Scott

Thanks Scott
I appreciate your advise. I have read the term 'Shock' used many times but never understood what it meant. I am assuming that it means adding a lot of chlorine? Can you enlighten me on what to do?
Thanks
Mike

Mike:

You can read through Pool School, the link is at the top right of this page. There is a section on "shocking" that will walk you though the process. You will see (or be told to) "get a good test kit", but since you are not in the US, I am at a loss as to recommendations. You might ask Dave / Duraleigh who handles my choice (TF Test kits) but I believe he is not allowed to ship overseas.

You can also google shocking (at the bottom left) and see how others have been coached though the process. And if you have problems, ask, there are a lot of helpful people here.

Thanks Buford, I have a TF test kit and will try your advice on using the Pool school or Google
Regards
Mike

Hello Again
This is where you get to see what a Muppet I am but I need help! I have printed off the Pool School data regarding how to 'Shock Your Pool' I am unsure of what item 2 means, 'bring FC level up to shock level' I am assuming that it refers to the tables shown in Chlorine/CYA Chart. If so, what are the figures shown in each column of the chart?
My last recorded figure for CYA was 30, does that mean I should have a minimum value for FC of 2 and a target of 4? What does the figure of 12 in the Shock FC column mean? is it about how much chlorine I have to add and is that figure grammes, kilo's, pounds etc.,
I apologise if this is Kiddies chemistry stuff but I am a long way past being a kid although my wife would say something different.
Best wishes
Mike

Plug in you test reading to the Pool Calculator to get the shock level for your pool.

http://www.poolcalculator.com/

Hey, Mike,

Posting current test results is, by far, the best place to start. That CYA of 30 may have changed (a lot) so we need to know where you are starting from.

Hello

I have just carried out another full test using the Taylor TF-100 kit with the following results: -
FC-2.5, CC-0, TC-2.5, pH-7.8, T/A-80, CH-290, CYA-30.

My pool is rectangular 12m long by 4.5m wide and 1m deep total water content 54000 liters. I have entered those figures into the pool calculator
Using the pool calculator recommendations I should add 88 grammes of Dichlor
1899 grammes of Baking Soda
540 grammes Stabilser, I note that Borate can be used as a stabiliser but what is it, does it have a trade name and will it be possible to buy it in the back end of nowhere?
I will add the Dichlor and Baking Soda as those are easy to get but the Borate????????????
Thanks for all the helpful comments and advice
Regards
Mike

I'm not sure we are identifying stabilizer as the same thing so I'm going to try and make sure we are on the same page. At TFP, when we mention stabilizer, conditioner, or CYA we are referring to cyuranic acid. Cyuranic acid protects the chlorine from the sun and helps it to maintain a longer effective life in order to sanitize the pool. Too much will prevent the chlorine from being effective at "normal" levels and requires increased levels of free chlorine to do the same job. We recommend cyuranic acid levels between 30-50 for pools without a saltwater chlorine generator. According to your test results you are at 30ppm for CYA now. The most common dry chlorine contains either calcium (calcium hypochlorite) or CYA (trichlor and dichlor). There is a dry chlorine made with lithium but it is very expensive and more difficult to find.

It looks like you are using the traditional pool levels in the pool calculator. If you add 88 grams of dichlor and 540 grams of stabilizer you will raise the CYA level to approximately 41 ppm. That is still within acceptable levels, but I would rather you switch to the TFP recommended levels using the drop down box on the bottom right of the page.

As for adding borate, it acts as a water softener and a mild algaecide, but it will not at as a stabilizer or substitute for CYA. You may be able to purchase 20 mule team brand Borax where laundry supplies are sold. When you use borax you also use muriatic acid (MA) to drop the pH to stay within recommended levels. You may find a drug store, chemist, or exterminator that will order boric acid in bulk for you. If you use boric acid you will not need to use MA with it.

The 1899 grams of baking soda will raise your total alkylinity (TA) to 100. It is not necessary to raise your TA at this time, but you can if you want.

In your post from earlier today you asked for help with this question


It says you should maintain your FC at 2-4 ppm, with 4 as the ideal. You want to keep the FC at the top or target of your range. If you let the FC fall below the recommended range you are at risk of developing algae and there will not be enough FC to sanitize the water. To complete the shock process, you would raise the FC to 12ppm and try to keep it there until the shock process is completed. You can use shock levels from the pool calculator or the cya/chlorine chart to complete the shock process.

I hope this clears things up somewhat.

Thank you very much for taking the time and trouble to assist me, it is gratefully appreciated. I will try to keep the FC at 12ppm now that I know what it means and see what happens over the next few days.
"I would rather you switch to the TFP recommended levels using the drop down box on the bottom right of the page" Sorry about this but what page and where?
Regards
Mike

The bottom box on The Pool Calculator is where you select which method the pool calculator uses to generate recommendations.

As for getting borax or boric acid, see this thread on a Thailand forum for some ideas. It sounds like you can get boric acid where they sell welding supplies since it is used as welding flux. You'd want it to be pure, though. It's also sold as an ant killer (insecticide). If you get boric acid instead of borax, then you won't need to add any acid so is more convenient, though possibly more expensive (if you can get Borax, that is). See also this thread on another Thailand forum where it says you can get borax by asking for sodium tetraborate from chemical houses. Also looks like this site sells borax.

Hello everyone
Thanks for the recent advice both helpful and informative. This is the state of play today 8am 11th Jan.
Yesterday I added Chlorine and Baking Soda, the amounts as calculated from the pool calculator, I also brushed the side of the pool and then covered it to protect the Chlorine from the Sun's rays. Today's test results are as follows: -
FC- 4.5 (up 2 points from yesterday)
CC- 1 (up 1 from yesterday)
TC - 5.5 (up 3 points from yesterday)
pH - 7.8 No change
T/A - 90 (up 10 from yesterday)
CH - 325 (up 35 from yesterday)
CYA - 20 (down 10 from yesterday)
I tried brushing the pool base today but the water was so cloudy I could not see the bottom, however, after doing the best I could, backwashing got rid of a lot dirty water/Algae?
From today's results, according to the PC I should be adding 442 g of Chlorine, 336 litres of Muriatic Acid, 1899g of Baking Soda, Replacing 8% of water and adding 2920 litres of Stabiliser. The pool holds 54000 litres.
I am OK with the Chlorine and Baking Soda/Soda Ash?
I have Hydrochloric acid will that do for the Muriatic acid or stabilser?
I am at a loss as to how to measure 8% of water to replace
I apologise once again for what are probably blindingly obvious questions but I am not confident in my understanding of the Acid issues. With regard to the Boric Acid, we do not have any laundries anywhere near where we live but I will be going to the city where I bought the Hydrochloric acid and will may be able to get it there, that will not be for a week or so. Is there anything else I can do until then with the hydrochloric acid?
Regards to all
Mike

First thing right now is to disregard all your test results except FC and CC until you're done shocking. Even though the Pool Calc says to add all those other things let's concentrate on just the chlorine for now. Getting your FC to 12 ppm and keeping it there using bleach or liquid chlorine is paramount right now. We'll deal with the rest of the results once you pass the OCLT (see link in sig for info).

Hello
Thanks for the email, I have just tested for tonight and will check again first thing tomorrow as you recommended. I have chlorine granules, does turning them into a solution with pool water count as liquid chlorine. Sorry if that's a stupid question but I need to get this water problem sorted out and not take longer than needed by using the wrong stuff. If that is not correct what strength of bleach would I need to get?
Regards
mike

The granules will have another ingredient in them besides chlorine. If they're calcium hypochlorite it will add calcium to your pool. Given that your CH is 325 I wouldn't want to be adding a lot more to it. If however they're Dichlor they add a lot of CYA to your pool. While you can use some CYA, I wouldn't recommend using it for shock because it will add too much too quickly.

So to answer your question -- No -- adding the granules to water won't exactly make liquid chlorine in our definition of the term.
When we say liquid chlorine, we usually mean between 5% to 16% sodium hypochlorite in water with nothing else added.

Hello Again
I have just carried out the morning test at daybreak and found no loss of FC/CC, Last night I recorded 3.5 FC and .5 CC, this morning 4 FC and zero CC. How critical is it that exactly the same amount of R-0870 for each test is used as the little spoon is so small that I feel I may have used different amounts. I am not too happy that I got that right so I will do another test tonight.
The Chlorine granules that I have been using are from Japan and labelled J-CHLOR, Calcium Hypochlorate available Chlorine 70 - 75%. Is this OK? I hope so as another supplier is a long way from here and you never know what brand you will get.
I am still unable to see the floor of the pool at the deep end (1.6m) and only faintly at the shallow end (1.0m) I have found a Bleach product that has Sodium Hypochlorate in it with 6% Chlorine, would this be OK to use a shock if needed? Would I be better to use Bleach all the time?
I realise I am taking up a lot of your time and wish that I didn't need to but I am very appreciative of your help.
Thanks
Mike

The Calcium Hypo you have is fine to use but keep in mind that it adds calcium so you want to keep a watch on that.

The 6% bleach you found is the best thing to use for shocking as well as every day chlorination.

Hello
Thanks once again for your help I will let you know how things turn out.
Regards
Mike