After Heavy Rain

[hultbergs]

Quick question:

Our pool is less than a month old, we are proud first time pool owners, and we have been having heavy rain for the last four days. Today the weather finally cleared so out to the pool I went to check water chemistry and to start cleaning up. I have a 5 way test kit these are the levels I experienced this evening:

FC 1.0
CC between 1.0 - 2.0
PH 8.0 - added 16 oz of muriatic acid to get ph level down at 8pm this evening (will test again tomorrow morning) - Acid demand test called for 1 quart of muriatic acid
Akalinity tested at 150ppm - our water has high alkalinity and we've been working to get it down to normal levels for a couple weeks...it's steadily getting lower witht he muriatic acid.
CYA levels unknown
and Calcium Hardness levels unknown (will get this tested at the pool store this week).

Waiting for my vacuum hose and vacuum head to come in the mail so I can get this crazy dirt out of the pool; however, it was brushed really good.

My question is do I still need to shock the pool because of the heavy rain over the last several days if our chlorine levels look okay?

TIA!

 

[Richard320]

Welcome!

Great first post. The aeration caused by the rain pounding the surface of the pool coupled with your high pH is what drove the pH up. Nothing to get excited about. Perfectly normal and expected, and the TA will slowly come down as you keep adjusting pH. Each time you add acid, the pH drops and so does the TA. pH will rise, TA will not, at least until you add more of that high TA fill water. But it's easy to deal with

What concerns me is the 1-2 CC. In a perfect world, you wouldn't have any. Because ours is an imperfect world, around here we treat .5 or less as zero. You're well above .5. There's a real good chance you've got an algae bloom building.

How did you get algae? Stuff blows and washes in, and you don't have enough chlorine to keep it from growing. 1 FC is too low even for a pool with no CYA, and I'm guessing you have some CYA, because the majority of people follow the pool store advice and chlorinate with trichlor pucks and occasionally dichlor shock powder.

How to get rid of algae? High levels of chlorine sustained for a period of time. Explicit directions are given in the SLAM Process article. You might note that one of the prerequisites is a FAS-DPD chlorine test. You'll also need to know your CYA, and the pool store test won't cut it. You're going to need to invest in a proper test kit.

Head on over to pool school and do a little reading. Start with ABCs of Pool Water Chemistry and then maybe move on to recommended chemicals, how to chlorinate, poolmath, test kits compared, and of course, SLAM Process

It's a lot to digest, and people have mentioned drinking from a fire hose, but it's not really all that difficult. If all you're showing is high CC, it shouldn't take but a day or two to call the SLAM done. As an aside, it is safe to swim up to [FC/CYA]shock level for your CYA[/FC/CYA], so the pool doesn't necessarily have to be shut down. Swimmers will just slow it down a bit.

 

[hultbergs]

Thank you Richard320,

What I have is powder plus shock from Leslie's, along with the Leslie's tab in our chlorine feeder line.

I went ahead and shocked the pool with the powder plus but after reading on Leslie's website, it doesn't look like the powder plus is good for pebbletech surfaces. Not very happy about that.

I tested the ph again and it was below 7.6 after adding the muriatic acid four hours ago.

I will definitely be educating myself as you suggested.

 

[JimMarshall]

Thank you Richard320,

What I have is powder plus shock from Leslie's, along with the Leslie's tab in our chlorine feeder line.

I went ahead and shocked the pool with the powder plus but after reading on Leslie's website, it doesn't look like the powder plus is good for pebbletech surfaces. Not very happy about that.

I tested the ph again and it was below 7.6 after adding the muriatic acid four hours ago.

I will definitely be educating myself as you suggested.

Powder plus is just calcium hypochlorite, correct?

If so, it did no damage to your pool other than raising your CH level. This is only “damaging “ if your CH was high to begin with.

 

[hultbergs]

Thank you so much for the feedback! My levels are finally okay. Apparently my test kit does not give accurate readings for chlorine, all my levels were fine except my alkalinity, it was just a little high. After adding muriatic acid everything is where it should be for now. My cc level was actually at zero, my test kit was totally wrong.

 

[JimMarshall]

Thank you so much for the feedback! My levels are finally okay. Apparently my test kit does not give accurate readings for chlorine, all my levels were fine except my alkalinity, it was just a little high. After adding muriatic acid everything is where it should be for now. My cc level was actually at zero, my test kit was totally wrong.

Yes, your test kit is not one that we recommend, but what are you basing this most recent analysis on?