Inherited a pond, trying to turn it into a pool!

[Yeggim]

Given that I'm still backwashing fairly regularly, and therefore replenishing water from time to time, would it make sense to leave the CYA until the filter runs for rather longer, instead of diluting it when I top the water up?

Sounds like a plan.

At 12.5% overnight loss in an unstabilized pool, can I start letting the level drift down yet?

Thanks as always...!

Sometimes the testing times will influence that overnight loss number. With low CYA, testing a little too late after sunrise or a little too early before sundown might account for that extra 1ppm. What's your CC numbers?

[barma16]

Sometimes the testing times will influence that overnight loss number. With low CYA, testing a little too late after sunrise or a little too early before sundown might account for that extra 1ppm. What's your CC numbers?

Interesting you should say that - I was worried about going too far the other way. I'm testing at 10pm, so the sun is well down, and 6am (which, frankly, is a pain) so that the sun hasn't been up too long. Up at 6 again tomorrow - will post CC numbers then...

[Watermom]

As long as you test within two hours of sunrise, it is fine.

[barma16]

Apparently no change overnight. 13.5ppm last night, 13.5ppm this morning. 1ppm CC. This seems a little too good to be true, but I tested twice this morning and got the same result. I'm working on a 10ml sample though, so perhaps there's less than 0.5ppm lost... Either that, or my testing is suspect again

I guess we'll have to see what happens tonight...

[Watermom]

Good news on the chlorine levels overnight! Since you still have CC of 1, keep it at shock level again today. Just use the 10ml sample. No reason to waste the reagents and 0.5ppm accuracy is close enough.

[Yeggim]

Excellent news except for that CC reading. I'd give the entire pool a good brushing, especially the corners and the walls. Afterwards I'd jack that baby up to 20ppm Chlorine. It could be the knockout punch of this epic battle.

I think you're way ahead on the scorecard but I don't trust that judge from Algaeria. You've really done an outstanding job thus far.

[barma16]

I think I can finally claim victory - three nights in succession with no FC loss. CC tested today with a 25ml sample is 0.2ppm or less - one drop cleared the solution. The filter has run for three days straight without gaining more than a couple psi.

So... I'll let the CL drop down to 6 or so, check and adjust pH, and then add some CYA. Back on page 1, when I thought I had 40k gallons, 6lb of CYA was recommended. Now that I know I'm actually around 20k gallons, I assume I should add about 3lb? I guess once I get all my levels within the ranges here: http://poolsolutions.com/gd/poolsolu...try-guide.html then I'm good to go?

[Watermom]

Awesome news -- finally!! Congrats!

In a 20K gallon pool, 3 lbs. of stabilizer will add about 20ppm of CYA.

Ranges:
Chlorine --- based on your CYA level. See the Best Guess chart in my signature below. (If you let the cl dip too low, you'll risk an another algae bloom.)
pH -- 7.2-7.8
Alk -- 80-125
CH -- not needed in a vinyl pool

Stay in these ranges and yes, you'll be good to go! Test chlorine daily, pH once or twice a week, alk every 2 or 3 weeks.

Enjoy your pool!

(For reference, in your pool, each quart of 6% bleach will add about 0.8ppm of chlorine. Use that to help you determine how much bleach to add each evening when you test.)