Saltwater pool, can't get rid of algae

[newnick]

These high temps and alot of trees make it tough in Texas.
My advice is to follow what's been said already and keep reading, it will come together.
This is our third season with pool, second to open a pool and it took only a couple days to get the pool sparkling, but the trees keep me busy!

 

[agarza8543]

Yesterday I scrubbed walls and floor of pool, then vacuumed as much as I could. Add 8 of the regular size jugs of bleach and 4.5 lbs of ph Minus. ( I added the ph Minus first, then waited until sundown to add the bleach).

The algae situation looks better this morning; though I think most of that is from all the scrubbing and vacuuming I did yesterday. There are still patches on walls and floor of pool and there are also alot of smaller (smaller than a dime) black patches that I was unable to remove; I scrubbed and scrubbed and some came off easily, some did not.

The water is clear.

This morning my readings are:

Total Chlorine - 10
Free Chlorine - 5
PH - 8.2
Alk - 120
CYA - 40

The shock chart says that my FC should be at 16....I just realized that my new test kit only measures up to 10!

So my FC "might" be ok, don't really know because of the test. My PH is still too high; what can I do about this? I add the PH minus as directed but it only moved it by .2.

Do I need to get the muriatic acid? I got a little scared about using the muriatic acid after I read all of the cautions about getting burned.

Thanks for your help.

 

[frustratedpoolmom]

From the description the small black patches sound like Black Algae. Brushing these spots to 'knock of the heads' is essential - their tough outer shell is resistant to chlorine. You have to brush them daily to allow the chlorine to attack the insides/roots and erradicate them.

Once you have your good kit, the FAS-DPD test will confirm accurately your chlorine levels. If what you are posting is correct you have a ways to go, to reach .5 on the CC level. You can use 1 part pool water to 1 part distilled or chlorine free water, to test your chlorine up to 20. You will lose some accuracy this way but at least you'll know if you are hitting 16.

Yes, use muratic acid - not PH minus. Don't be afraid - many use it, just take appropriate precautions. They have different strengths available, some have less fuming then others so if you want to start with the lesser strengths that's okay, just select the appropriate % from the drop down menu of the pool calculator.

 

[fuzzy_dba]

...Add 8 of the regular size jugs of bleach and 4.5 lbs of ph Minus. (ph Minus first, then waited until sundown to add the bleach).
...still patches on walls and floor of pool and there are also alot of smaller (smaller than a dime) black patches that I was unable to remove; I scrubbed and scrubbed and some came off easily, some did not.
The water is clear.

This morning my readings are:
Total Chlorine - 10
Free Chlorine - 5
PH - 8.2
Alk - 120
CYA - 40
The shock chart says that my FC should be at 16....I just realized that my new test kit only measures up to 10!

So my FC "might" be ok, don't really know because of the test. My PH is still too high; what can I do about this? I add the PH minus as directed but it only moved it by .2.
Do I need to get the muriatic acid? I got a little scared about using the muriatic acid after I read all of the cautions about getting burned.

Muratic isn't hard to use as all. Just take the necessary precautions: safety glasses (good for all chemicals), rubberized gloves, always add acid to a container that already contains water (don't add water to acid), and DON'T inhale fumes!
-Yea, some of had to re-learn about hydrochloric acid fumes from high school chemistry all over again!
Remember that PH readings are not accurate when chlorine levels are high. The have a tendency to read higher than they are.

You can dilute the pool water with distilled water (50-50) and re-run your chlorine test. Double the value that you get and that's a close ballpark value to your actual chlorine.
The TF100 test kit will measure up to 50PPM of chlorine, and it's so easy to use. ...HINT...

If the spots won't come off they may be black algae. Scrub them , keep at shock level, scrup them again , keep at shock, etc. You scrub the top layer off, the chlorine gets to the next layer, scub that dead layer off, the chlorine gets to the next layer, etc.
You ARE getting there!

Terry in NC