How Much FC?

[Justinmc]

New(ish) pool owner, new to the TFP method. Bought a home with a pool a year ago, used jumbo pucks brushed it once a week, and pretty much left well enough alone. Just had my water tested at a pool store, here's what it came back with:

FC-3
CH-540 (anyone need any calcium?)
CYA-100 (I'm guessing that's all their test went up to)
TA-120
pH-8
TDS-2500
Pho-300

What I think I know so far based off the forum, feel free to correct me!:

I'm going to stop using triclor, I know the CYA it contains just adds to the problem. I'm currently scoping out bleach and liquid chlorine prices and taking into account strength and bottle size. I most likely should drain around 60% of my pool to lower the Calcium and CYA to appropriate levels. Small problem, I live in California, it's drought season, it's summer, and it would cost me north of $300 to do a partial drain, so I am looking for temporary alternatives to keep algae away and just get through the peak water price months.

Pool Math tells me my target FC should be 4 ppm....I might have done something wrong. Ok, I probably did, given my CYA.

What should my FC be given the high CYA, and how much bleach or liquid chlorine should I use to achieve that? Also, should I test my chlorine levels daily, and based off that test, how do I determine how much chlorine or bleach to put in each morning? While I know there are better test kits the forum suggests, all I have IS a little Taylor k-1004 for now.

Thanks in advance for helping out a newbie!

 

[jblizzle]

Welcome to TFP!

You should certainly get one of the recommended test kits that includes the FAS-DPD chlorine test sooner than later. You need to know the CYA level to know the minimum FC level. There is a chart in the handy reference area of Pool School. At a CYA of 100ppm, the minimum FC you must maintain is 7ppm ... Your test does not go that high, thus the need for the FAS-DPD test.

But, your CYA is likely even higher than that making the minimum FC level higher too.

Ultimately, you need to get that water replaced. You may have reverse osmosis treatment available to you, but it costs more than what replacing the water will cost. Those are the only 2 ways to lower the CYA.

 

[Justinmc]

BTW, I read the Pool School Chlorine/CYA chart and it suggests a minimum FC of 7, target FC of 12. Is that right?

- - - Updated - - -

Thanks Jason, you beat me to it about the Pool School chart.

 

[snipeorod]

Welcome to TFP, I was in your situation when I first started and this forum really helped me out. I thought I had a CYA of 100 but after diluting the sample I found it was much much higher. In order to do this right you need to find your true CYA. Once I did that the rest was easy. I now have a balanced pool. Of course getting one of the recommended test kits is a must. After my last drain I would say I drained at least 3/4 of my pool. I too am in California and on a water meter but when I received the bill I was pleasantly surprised. It was no where near what I expected.