Suddenly cloudy water and low ph

[truta11]

First post from a newbie.

Thanks for all the help this forum has been so far. My apologies for the rambling message below.

I have a 14,000 gallon in ground pool with a vinyl liner, sand filter. Bought the home this February, my first pool. The water has been crystal clear and almost perfect for about a month now, the kids have been swimming in it multiple times a day. For some reason, no one swam on Friday, and we left our new solar blanket on during the day, maybe for 36 hours. Grandma and grandpa came to visit Saturday, and when I pulled the cover off Saturday afternoon the water was very cloudy, I can barely see the bottom of the 3 foot area. Murphy's law...

I've been using Tri-Chlor as my chlorine source in an attempt to raise my CYA just a bit more. My feeder started leaking the same day that no one swam, and I turned my pump off overnight rather than fix the leak immediately. The chlorine also dropped to near zero on the day that no one went swimming, since I didn't get out to check it. Since the pump was off and the chlorine was low, I immediately suspected an algae or cc problem. The color is more whitish than green and is not slippery feeling.

When I saw that the pool was cloudy I immediately used 12% bleach to bring the level to 13 ppm FC to try to shock it, and it has dropped naturally now to 6.5 after about 24 hours. CC still reads just barely above zero though.

My latest test results using the Taylor kit are : FC 6.5, CC 0+, TA 110, ph <7, CYA 30, CH 150, temp 86 °F.

I have been struggling with my ph for a while now too. I've added several boxes of borax and the level will rise for a little while and drop back down again quickly. I got it up to 7.4 late last week, but it has now dropped again to below 7, despite another box of borax. The latest drop occurred after disconnecting the Tri-Chlor feeder due to the leak.

My water level also had dropped due to the leak, so I've been making up water from the municipal water supply. Its ph is at 7.4, and it is quite hard.

I also backwashed the sand filter this morning after no apparent change in water quality overnight. The pressure was around 22 psi, it's now down to about 18 psi.

So, I have two problems- difficulty raising and maintaining ph, and suddenly very cloudy water. My plan of attack is to try to raise ph and maintain FC at or near shock until it clears.

Any other suggestions?

Picture from earlier this week and today.

 

[Butterfly]

Your plan sounds good. Follow the Shock Process in Pool School. You will be done shocking when you pass the three tests. See red lines in my sig.

The reason you have had problems with the pH is the trichlor pucks. They can cause pH and TA to crash if not monitored closely.

Beautiful pool. Welcome to the forum

 

[chem geek]

So, I have two problems- difficulty raising and maintaining ph, and suddenly very cloudy water. My plan of attack is to try to raise ph and maintain FC at or near shock until it clears.

Welcome to TFP!

That's a fine plan. Just raise the pH to 7.2 before you shock since the chlorinating liquid or bleach that you add will raise the pH when you add it. You can deal with a final pH adjustment after your pool clears up and you've let the chlorine level drop back down. Be sure to keep a minimum shock FC appropriate for your CYA level so if CYA is 30 ppm then that's 12 ppm FC minimum so have it be higher so that the next time you add more chlorine it's not below 12 ppm. Run your pump 24/7 to speed up filtration of the likely dead algae.

Your pH has been dropping because Trichlor is very acidic. When you stop using the Trichlor, it should be easier to maintain the pH.

 

[Casey]

You recieved sound advice so all I'll say is welcome and nice pool!

 

[truta11]

Thanks for the reassurance. Any pros or cons to leaving the cover on or off?

 

[Butterfly]

Leave off to allow sun to help burn CC.