New pool and trying to balance the water.

I just bought a house that has an IG pool. It is a vinyl liner pool that holds between 18500 to 19000 gallons. The previous owner used the nature2 system with an inline chlorinator. After reading posts on this sight, I have taken out the cartridge in the nature2 and turned off the inline chlorinator. I went to a pool store about a week ago to have them check the pool water and this was there result.

FC: 0 PH: 6.8 TA: 100 CYA: 25 CH: 180 TDS: 600 Copper/Iron: 0 Phosphates: 200

I have since tried to use the bbb method to balance the water by adding 6% bleach and using borax. I can't seem to keep chlorine in the pool very long. So far every night when I check the water the chlorine levels have been around .5 to 1 ppm. I keep adding a whole bottle of bleach to bring up the chlorine but by the next day, most of the chlorine is back to .5 to 1 ppm. I have purchased the test kits that are recommended on this site and this is the test results I got about 20 min ago.

FC: .2 ppm CC .4 ppm pH: 7.0 TA: 30 ppm CYA: 50-55 ppm

I would love to know what I should add and in what order. I have purchased more Borax, 6% bleach, and 12.5% bleach. I still need to buy acid. I greatly appreciate any help.


Matthew

Hi Matthew;

1. Add a box of borax -- slowly, to the skimmer, with the pump on -- and 4 gallons of 6% bleach or 2 gallons of 12% bleach this evening.
2. Test your chlorine level tomorrow AM, and again tomorrow PM
3. Repeat the borax doses, till your pH is above 7.2
4. Continue the bleach doses, till your AM FC levels is more than 12 ppm AND your CC levels is less than 1 ppm
5. Skip bleach doses if your chlorine level in the PM is more than 6 ppm.

The FC = 0.2; CC = 0.4 suggests you have a fair amount of oxidizable goo in the water. It could be a little or a lot; it could residue from bacterial biodegradation of stabilizer, or it could be cheap algaecide used last fall. There are two ways that I know of to get a handle on this:
(1) you could take your water to a EPA certified lab, and have them do a COD test (Chemical Oxygen Demand) done for $$$. Then you could convert that to a estimate of total chlorine needed.
(2) you can dose with chlorine till you can (a) hold a residual overnight and (b) have a low CC relative to your FC.

I recommend the 2nd option . . . since you have to DO the same thing, in either case. Even if you know how much you have to oxidize, you could damage your pool if you try to add 125 ppm FC to your pool all at once. The only reason I mention it, is that we currently have several poster in similar situations, who are frustrated that their chlorine keeps disappearing, and that we can't tell them when they'll be done.

Let us know when things seem to stabilize. You'll also need to think about how you want to chlorinate over the summer. One possible combination -- especially if you can conveniently by FRESH 12% bleach, and have a way to carry it without messing up your vehicle (it's VERY corrosive) is to shock with bleach 1x per week and use trichlor in the skimmer or a floater in between to hold chlorine levels.

Good luck!

I would also suggest using the 10ml sample to test instead of the 25ml sample. It will make the reagents in your kit last longer. Welcome to the Pool Forum!

Okay I will give it a try. I did the chlorine and the borax this evening. When you say to continue adding the bleach doses, does that mean the 4 gallons of 6% bleach at night, or if its below 12 in the am I just need to bring the levels up to 12 ppm?

Thanks for the help.

Matthew

You can keep it simple, by adding 4 gallons each time (while you're still doing clean up), but skipping if your PM chlorine is > 6 ppm.

Okay. I am not sure if it makes a difference but it has been raining pretty steady the last few days. Do I still treat the pool or wait till the rain stops. This morning when I checked the water the FC= .5 and the CC= .5.

Treat the pool or it will turn green!

What does PF=>6.5 in your signature mean?

Not sure what it means. I don't think I put it there. Thanks for your help.