Utter noob with a pool but good general mechanical knowledge.

Mudster

Member
Sep 2, 2019
5
Bergerac
Visiting a friend in France and hes asked me to help. His pool is approximately 15, maybe 20 years old, he's not sure. He has lived here for 8 years though and so far as he knows there has been no maintenance carried out since his tenure. The sand has never been changed (im a bit worried about doing that) although i do have patients and wont be vacuuming out the old if necessary, I'll do it by hand. He now has algae in his pool. I have nothing here apart from pastilles, and some shock tabs.. and a 5 ltr container of chlorine I guess. anyway, im off to the pool shop tomorrow. My question is, is there anything i should prioritise when trying to move forward with this problem? Do I need to buy test equipment first? is there anything i should look out for in a poorly maintained pool? Apart from algae I reckon its pretty clean, nothing of any substance but when I vacuum it doesn't take long for me to see the algae recycling. I'm sorry its short notice and I'm going to have a good read this evening. Just trying to help a friend and have to be back in the uk Friday. dont speak much French but I can get past that.. Just a few pointers or links to posts I might read here. Cheers Guys. .V,
 

ajw22

Gold Supporter
TFP Guide
Jul 21, 2013
18,959
Northern NJ
Chlorine is the only thing that kills algae. Don’t get sucked into pool store potions and algaecides. Find pure bleach or liquid chlorine if you can.

You know about pool water chemistry and CYA? If not read ABCs of Pool Water Chemistry.

Without knowing the CYA level you don’t know how much chlorine you need to add to kill algae. We have the SLAM Process and FC/CYA Chart but you need a test kit that test chlorine over 10 ppm and test CYA levels. You don’t find those in stores.

Post pics of the labels of the chemicals he does have. You have to improvise and become a pool water chemist.





 
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Mudster

Member
Sep 2, 2019
5
Bergerac
I hope to purchase a tool to undo the filter as well, as the sand has never been changed. Is that a priority? Its not been opened in at least 15 years.
 

ajw22

Gold Supporter
TFP Guide
Jul 21, 2013
18,959
Northern NJ
You want to use that bleach against the algae. The tablets will add unwanted chemicals.

See what tests you can buy at the pool store or what water tests they will do. You want to know free chlorine, CYA, and pH.

You need some acid, preferably muriatic acid, to lower the pH.

We use PoolMath to calculate the effects of adding chemicals.

Filtering does not get rid of algae. Chlorine does. Filtering will clear cloudy water of dead algae. Focus on killing the algae first before you focus on the filter.
 

Mudster

Member
Sep 2, 2019
5
Bergerac
You want to use that bleach against the algae. The tablets will add unwanted chemicals.

See what tests you can buy at the pool store or what water tests they will do. You want to know free chlorine, CYA, and pH.

You need some acid, preferably muriatic acid, to lower the pH.

We use PoolMath to calculate the effects of adding chemicals.

Filtering does not get rid of algae. Chlorine does. Filtering will clear cloudy water of dead algae. Focus on killing the algae first before you focus on the filter.
Great info, thank you. I'll use that bleach over night and get some more. had to order a tool to open the filter anyway, that will take a week to arrive here and I'm off home Friday. Probably come be back in 10 days and have to start again. can I use as much bleach as I like?

Thanks again. ,
 

ajw22

Gold Supporter
TFP Guide
Jul 21, 2013
18,959
Northern NJ
can I use as much bleach as I like?
Too much bleach creating too high a FC level can bleach the colors from the liner. Don’t know the way the liner looks and the liners age.

If you knew the CYA and could test FC levels, up to SLAM FC level on the FC/CYA Chart is safe to swim and will not affect a liner.