Help!

[mdpennin]

I have a 30,000 gal inground pool with a chlorinator and sand filter. Currently, my husband has been taking a sample of pool water in to the local pool store and letting them tell us what to add. However, this is not working! We are struggling to keep chlorine detectable and our water is cloudy. I bought the 6 way test kit tonight and this is what I came up with:
Total chlorine 0.5ppm, total alkalinity 150ppm, pH 6.8, total hardness 200ppm, CYA 30ppm

We were looking forward to swimming this weekend. Can anybody advise what we need to use to get on the right track?

Any advise would be appreciated

 

[JasonLion]

Welcome to TFP!

Do you have any test kit of your own? Various steps require adjusting a level, testing to see where you got, and then adjusting again. In the short run even a very simple test kit is much better than nothing, but in the long run there are huge advantages to having your own top quality test kit. The first step to solving any problem is knowing what is going on with your water.

The first thing to do is to bring your PH up to at least 7.2. Since the standard PH test only measures down to 6.8, and reports anything below 6.8 as if it was 6.8, it may take a couple of tries to get the PH right.

Then you want to add chlorine up shock level (around 15 for you right at the moment) and see what happens. Without chlorine in the water you could easily slip into a full algae bloom.

One issue here is that your CYA level is on the low side of normal (assuming we trust the pool store results, which isn't always a good idea). You will be losing more than half of your chlorine to sunlight each day. You can partially compensate for that by adding chlorine in the evenings, so it has all night to work before sunlight starts breaking it down.

Meanwhile, I strongly recommend you do some reading in Pool School, see the link near the top right of every page.

 

[woodyp]

Fix your PH first. Take your pool to shock level with LIQUID bleach (clorox) and let your filter run a solid 24 hours and see if it clears. You might get lucky and avoid a full shock PROCESS. Only test results will tell along with water clarity. Pay close attention to the CYA/chlorine chart in pool school.

 

[mdpennin]

Thank you for your quick responses. So if I am understanding this, the first thing I should do is add borax (3.3 boxes of 76 oz powder) to try to raise my pH? Once I do this, how long should I wait to retest my pH? Once I get the pH up, then I can add bleach 6% to shock level?
How long do we need to wait to swim?

 

[duraleigh]

You can swim this weekend if you want but your pool will most likely not be clear, The shock process, if you do it correctly, will take a few days and you haven't started yet.

This is a hard pill to swallow sometimes but your pool did not get in it's current condition in 24 hours so you cannot expect to clear it in that same time. read "The ABC's of Pool Water Chemistry" up in Pool School. Then, read "How to Shock Your Pool" up in Pool School. Those articles will get you on your way to managing your own pool and having crystal clear water all summer.