Help with numbers
- Thread starter nabril15
- Start date
Yes.
You used the magic word: algae.
You'll need to be patient and let the FC drop a little (10 or less) first, so you can accurately test and adjust the pH. Then you can go up to shock level of 24 FC. And then maintain it....SLAM Process
If you're getting in to clean behind the light. connect the vacuum hose and have it handy while brushing inside. See the pictures Think I may have found my FC demand issue?
Thank you Rich. I've had to do this in the past, where I had to let FC drop to be able to test the pH. But, I ask. Since I'm already at an FC of 13, what would be the harm in just continuing up to 24 to begin the SLAM? I know that the pH has to be lowered BEFORE a SLAM, but I confess that I don't know why it has to be done; it is not explained in the SLAM page.
- Jun 22, 2014
- 52,213
- Pool Size
- 17888
- Surface
- Fiberglass
- Chlorine
- Salt Water Generator
- SWG Type
- CircuPool RJ-45 Plus
The reason is because the elevated FC level will cause the pH to rise as well. We just don't like to see a pH get too high for an extended period of time. Once the SLAM is over and the FC is allowed to fall, the pH should go back to normal.
Thank you TexSplash. I assumed that was the case, but in my mind it sounds weird to read that adding chlorine will raise pH.
The pH rise is only temporary.
From here: Key Misunderstandings and Problems in Pool Water Chemistry (Part I) - AQUA Magazine
"Liquid chlorine does not raise pH. When added to water, liquid chlorine (which has a pH of 13) makes HOCl (hypochlorous acid – the killing form of chlorine) and NaOH (sodium hydroxide), which raises pH. But when the HOCl is degraded by UV, and when used in killing and oxidation, it creates HCl (hydrochloric acid). The amount of HCl is almost identical to the amount of NaOH. So the net effect on pH is zero (or almost zero)."
Once the chlorine is eaten up by UV light it leaves behind Hydrochloric acid which lowers your pH back to normal. The net effect is ZERO.... but temporarily, it rises.
thank you to both. So. Being that I'm at an FC of 13, could I continue up to 25, and add the equivalent to lower my ph down 3 points?? Two Saturday's ago, my ph was at 7.8, and I gained an inch or so of water from rain. So, what if I add the acid needed to bring 7.8 down to 7.2, and add 24 of chlorine? It just sounds "dumb" and wasteful to let my current 13 evaporate or lower to 10 just to measure the ph to bring it down, and then go back up.
I highly doubt you're still at 13 after 23 hours.
You were probably below 10 by lunch yesterday.
But anyway, it's your pool and you can do what you want. Just don't expect any of us to agree with shortcuts and skipping steps. We try for consistency here. Part of a SLAM Process is dropping pH to 7.2.
Those are valid points Richard. I thank you and I'll test my water in a few minutes.
Rich, I just tested to 13, and the sample water was still a bit pinkish. We didn't get much sun yesterday since it rained all day, so evaporation is out of the formula. Shouldn't I have lost some if I have bad algae??
Yes. But we already knew you didn't have bad algae. You wrote, "I brush a small amount of algae every morning."
Either do it right and be sure it's all gone or continue to clean up small amounts every morning. But small amounts tend to get larger over time.
thank you Richard. By "do it right" you are referring to the slam, right? I'm just making sure.
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