New to the forum - Trying to get a handle on pool chemistry

[CompostPile]

Howdy,

I have a 15'x48" Intex AG pool that the kids love. We set it up and used it for about 3 weeks when we got an algae bloom. I needed to take it down and get the ground level so we drained it and started over. Pool was great again for about a week and a half. Now its starting to turn green again.

I spent a few hours reading through a bunch of the posts and need to get a better test kit. The one I have uses drops but does not have anything to test CYA.

This evening I added a half a bag of HTH shock and swim and also muriatic acid to bring the ph down. It was really high (maxed out on the color chart). Tomorrow we plan on getting some bottles of bleach and using that to manage the chlorine.

I'll post the water test results when I get them tomorrow.

[aylad]

Hi, and welcome!

Did you add any stabilizer when you refilled the pool? If not, then the sun is consuming your chlorine very quickly and would explain why it turns green so quickly.

Post your water test results, along with the ingredients of anything you've added to the pool, and we'll be glad to get you going in the right direction!

[PoolDoc]

Meanwhile, add 1/2 gallon of plain 6% household bleach each evening, after you finish swimming or near sunset (which ever is later), till the algae is gone.

Ben

[CompostPile]

Just noticed I am able to post...

When I filled the pool a few weeks ago, I did use a half a gallon of liquid stabilizer that I had left over from when I filled it the first time. I had been using stabilized tablets in a floater until they were used up last weekend.

Had the water tested yesterday at the pool store while the good test kit is on the way
FC: 4.0
TC: 4.0
CYA: 50
TA: 90
pH: 7.6

I started to kill the algae with a big bottle (180 oz) of 6% bleach yesterday evening. I tried to test the water this morning and the cheap kit said it was at least 5ppm so I added another bottle. I didn't get home until it was dark so I couldn't tell if the green is turning to grey, but I still cant see the bottom. I did add another bottle this evening so I imagine the chlorine levels should be high enough to kill the algae. I'll post an update tomorrow after I can see the color of the water.

[CompostPile]

Morning Update...

Water is clearing up. I could see the bottom this morning. The color is turning from green to greyish white. There is a bunch of what looks like dirt on the bottom now. I'll set up the vacuum I have rigged up to try and clean that up tonight.

My cheap test kit had the color very deep orange which is different than when I tested the last couple of times so I think the algae is dying off and more chlorine is staying in the water.

[aylad]

The fact that the water is clearing and you're seeing evidence of dead algae is great...keep that chlorine level up, keep your filter running, and make sure to keep an eye on your filter pressure and clean it as needed. The chlorine will kill the algae, but it is the filter that will remove it from the water (other than what you're able to vacuum up)

You can force your cheaper test kit to measure higher chlorine levels with this method: http://www.poolsolutions.com/gd/how-...d-testkit.html

It's a ballpark, because you lose a little accurace with each dilution, but it'll be better than just guessing. You want to keep the chlorine level up at 15 ppm until the pool clears, and until you're not losing more than 1 ppm of chlorine when testing in the evening after sundown and again in the morning before the sun hits the pool. Once you're at that point, you can let the chlorine level drift back down, but with a CYA of 50, you never want to let it get below 3 ppm, EVER. And since your CYA is at the top of the range, I would keep it closer to 5 or 6 ppm if you can, just to give yourself a little wiggle room. (See the best guess chart at http://www.poolsolutions.com/gd/best...e-chart.html#a for a better explanation of that)

Janet

[CompostPile]

One question...

How fast does the CYA level drop? The new kit will not arrive until next week so I don't have a way to test if the CYA is dropping. I will continue to monitor the chlorine best I can and try to keep it at 15ppm until the pool is clear.

Jamie

[Watermom]

CYA levels are pretty consistent throughout the season once you add it. You lose a little to splashout and refill but over all, not much.

[CompostPile]

I ran the vacuum to waste last night. I could see a big color difference from where I vacuumed to where it still had junk and could see the color in the clear pump lines change to brown when I was sucking up the junk so it was really bad. I needed to refill about 5" of water after that was done so I also added one bottle of bleach to make sure chlorine levels were plenty high. This morning the water is a nice blue color, but still cloudy. I took a sample in to check CYA levels again and they said its now at 10 probably due to the changing out of so much water. I have some stabilized tables left over. Can I use them to bring the CYA level up some and supplement the bleach for chlorine or will that throw things off. I don't want to undo whats been done so far. Thanks so much for all the help so far.

Jamie

[aylad]

You can absolutely use the tablets to help raise the CYA levels--just keep an eye on your pH and make sure it doesn't get too low--trichlor tabs are acidic and can drive pH downward. It's fine to use the tabs and the bleach at the same time in the pool--after all, it's all chlorine when it gets in the water. Just don't let the bleach and tabs come into direct contact with each other before they're in the pool.

Janet