Trying to raise ph adding 20 mule team borax

Hi, I'm a new pool owner - 4 months now. Pool was green when I moved in and I luckily found this site before I was "pool stored". My pool is an 18' X 36' inground with a sand filter and inline chlorinator. I got my pool cleared up and the water sparkling clear by following the instructions here. After a few thunderstorms and neglecting to test every day(feeling stupid and guilty) my pool ph isn't even registering in my 5 way test kit from Walmart. I've added 8 boxes of 20 mule team borax now - started with half a box at a time, testing, then adding more, got exasperated and started adding a whole box at a time now just to get the water in the ph test to change from yellow. My chlorine level has been good it was about 3 on the test, went down, added chlorine, went back up to 3. I checked the ph reading against my tap water and it reads about 7.6 on the test so the phenol red is good, my pool is just out of whack. It is in full sun all day here on the Gulf coast of Florida - it's been in the 90's-100's lately with high humidity. More rain expected b/c of the tropical storm in the Gulf. Why did the ph go down? How much more 20 mule team do I need to add - I figured I've added 208 oz. so far. I can feel the changes in the feel of the water after it's added but the test isn't changing at all. I need advice, help, any reassurance what I'm doing is the right thing...

melanie612

That's an awful lot of borax to have no effect. I'm wondering if you might actually be super-alkaline and that's why.

But rather than waste a gazillion boxes of Borax, why not take a five gallon bucket of pool water and add Borax to THAT until you get a reading? I'm not sure how many cups of Borax are in a box, but you could start with 1/8 cup and see what that does, and add 1/8 cup until it registers. That will give you a baseline. If it STILL cannot do it, try going the other way.

Take a 5 gallon bucket of pool water and add about 10 ml (an eyedropper full) and see if THAT now registers--adding acid until it does.

If your pool really is super-acidic then the added bonus of adding all this Borax is your borate level should be approaching the ideal of 50ppm--which helps inhibit algae and helps keep pH stable.

I dunno--that's how I'd approach it.

Trichlor pucks are notorious for driving pH down because they are very acidic. Also, I find that when we have tropical storm/hurricane remnants come through, the rain actually causes a drop in my pH that "normal" rain doesn't do.

Janet

Thanks CarlD and Janet for your responses - I will try the bucket test CarlD and see what happens. I am using trichlor pucks and had a leak in the inline chlorinator that I didn't notice for about a week until I wondered why I had to replace them so soon when I checked them again - seal lost, wore out, don't know - it went missing and had to replace it. Now the chlorine puck use has dropped but I'm guessing that and the rains we've had probably made the ph drop from what you're saying - can't figure why it would be super alkaline. Thanks so much for the advice. I'll let you know what happens.

melanie612

The pucks can really mess up both your pH and your stabilizer levels. You have to watch both when you use them or...big trouble!

But when you can't find an obvious solution you have to find ways to isolate your problem. If somehow, you can't get a pH reading with the bucket, then something else is going on...but I don't know what--yet

Melanie,
How's your chlorine(does it keep dropping), CYA, and TA levels? How big's (gallons) your pool?
You could try mixing pool water and tap water at 1:1, 1:2, 1:4 ... until you get a clear reading to see if your pool water increases or decreases your tap water's PH.

If your 5-way test kit comes with a TA test (and bromocresol indicator), do a TA test and see if the indicator turns immediately red (as opposed to green).

If it turns red immediately then the pH is less than or equal to 4.5.

Hi, I never got around to posting what happened with the pool and adding borax. Here's what I did - instead of getting a five gallon bucket of my pool water I got about a gallon in a large measuring cup, then used one cup of the pool water to experiment with. I started by adding one teaspoon of borax at a time then testing. I finally got the test to the correct level. I then calculated how much that would represent in the ratio of my pool water to borax. I added 6 more boxes of borax to the pool and my PH tested 7.6 finally!!!!! I used the smaller amount of pool water b/c I thought it would be a faster method than using the 5 gallon bucket. I appreciate everyone's comments and suggestions - after that problem I had practically a worry free summer!!!!

I'm glad you got it back into range. Just a word of caution, though--if you have used enough trichlor to drive your pH down that far, then I'm guessing your CYA is way too high to just keep 3 ppm of chlorine in your water. Make sure you measure your CYA and use the "Best Guess Chart" here http://www.poolforum.com/pf2/showthread.php?t=365 to see how high you need to maintain your chlorine to keep from having to fight the algae again.

Janet

Janet makes an excellent observation.

Since you put so much Borax in your pool, it will be worth it to get Borate test strips (They measure the Borate level--which is what Borax adds). I will speculate that your borate level is fairly high, but probably not the ideal of 50ppm.

Still one of the beneficial side effects of a high borate level is its very strong algaecide property, which may be why you haven't had an algae bloom if, as Jan suspects, your CYA is higher than we normally recommend.

Carl