What to do first? CYA > 200 ppm

[PoolDoc]

Best time to add chlorine -- ESPECIALLY on a pool with low CYA -- is in the late evening.

[PoolLizard]

Best time to add chlorine -- ESPECIALLY on a pool with low CYA -- is in the late evening.

Understand, point well taken.

[PoolLizard]

Well, refill almost complete. Water level has about 8 inches to go.

I have my Bleach, Borax, and Baking Soda ready. As soon as the water gets up to skimmer level I'll get the pump primed and going, then I'll test the water to see where it's at.

So, what do you recommend I do first at that point?

From what I've read, I should first put some cyanuric acid in a sock and drop that in the skimmer basket. I'm thinking I should first shoot for a CYA level of 30. I will let the PoolCalculator figure out how much acid to put into the sock. Then I'll add chlorine AS IF the CYA was already at 30. That means a FC level of 4.

Then I'll adjust the TA and pH. My fill water has a pH of 7.7 and a TA of 90. So, I'm thinking that I'll probably have to lower the pH just a little.

[PoolDoc]

If you have access to a Sams Club, I'd buy 2 of their 24# boxes of bagged dichlor. Each 1lb bag will add about 2.5 ppm of chlorine, and 2 ppm of stabilizer (CYA). Once you've reached 60 ppm CYA (= ~30 bags of dichlor, on your pool), you'll want to switch to bleach. Dichlor ALSO lowers your pH, not immediately, but later. So, you'll need some of the borax on hand, to maintain your pH, but since your pH is starting a bit high, you may not need it aft first.

You can also use cal hypo, cautiously. It will add calcium which you will need at first.

However, you need to understand that with a pool in the desert, and with a DE filter, you are going to be constantly losing water to evaporation -- leaving all the minerals behind. And with a DE filter, you will NOT be losing water to backwashing. This means the replace water will ADD to the calcium present.

So, while you want to get your calcium up some now (maybe, 180) you don't want to hurry, and you don't want to go too far, since you'll also be adding MORE calcium every time you top off your water.

[PoolLizard]

If you have access to a Sams Club, I'd buy 2 of their 24# boxes of bagged dichlor. Each 1lb bag will add about 2.5 ppm of chlorine, and 2 ppm of stabilizer (CYA). Once you've reached 60 ppm CYA (= ~30 bags of dichlor, on your pool), you'll want to switch to bleach. Dichlor ALSO lowers your pH, not immediately, but later. So, you'll need some of the borax on hand, to maintain your pH, but since your pH is starting a bit high, you may not need it aft first.

I have a Costco nearby. I still have 11 1 lb bags left from the last box I bought.

You can also use cal hypo, cautiously. It will add calcium which you will need at first.

Still have some of that.

However, you need to understand that with a pool in the desert, and with a DE filter, you are going to be constantly losing water to evaporation -- leaving all the minerals behind. And with a DE filter, you will NOT be losing water to backwashing. This means the replace water will ADD to the calcium present.

Not sure I'm following you here. True, I do have a lot of evaporation, but I also do a lot of backwashing because even though this is a desert climate, my immediate area has a lot of tree leaves and other crud flying into the pool on a regular basis. Ergo, a lot of backwashing/filter cleaning.

So, while you want to get your calcium up some now (maybe, 180) you don't want to hurry, and you don't want to go too far, since you'll also be adding MORE calcium every time you top off your water.

Got it.

[PoolDoc]

Depending on what sort of DE filter you have, and how you clean (open & wash down VS. backwash), and how long you backwash, pools with DE filters tend to actually 'waste & replace' from 10% to 50% of the water that pools with sand filters use. This means that CYA, calcium, metals, etc. accumulate in such pools more rapidly than in pools with sand filters.

Of course, pools with cartridge filters tend to 'waste & replace' even less, maybe 5 - 10% of what pools with sand filters do.

[PoolLizard]

Okay, I just completed a cpmplete test of the refilled pool water. Here are the results:

FC 0.5 (10 ml sample)
CC 0.0
pH 8.0
TA 100
CH 100
CYA <30

So, I guess I'll start adding dichlor now.

[PoolLizard]

At 10:00am I added four 1 lb bags of dichlor to the pool.

At 11:00am the water test numbers are:

FC: 10
pH: 7.4
TA: 100
CH: 90
CYA Not tested. I'll wait until tomorrow to test that again. I'm waiting on my 8 oz bottle of R-0013 to arrive in the mail.

So, looks like I need to up the CH a bit.