No Chlorine showing up!!

[Preston]

Hi, i have a 40,000 gallon pool. We just opened it about a month ago and it's been a struggle to get chlorine to even slightly show up. We tried putting a very high concentrated shock bags into the pool a week ago and no chlorine. And yesterday we bought even more. Still not a trace of chlorine. The water is very cloudy and we are planning a pool party this thursday. I hope you guys may be of assistance to us.

[aylad]

There are several things that can be contributing to the problem--the most likely two scenarios are 1)testing with strips, which are being bleached out by high levels of chlorine, and 2) ammonia that was left in the pool when high levels of CYA from last summer were broken down by algae over the winter. So...

We can help, but we need to know more first. Please give us test results (drop-based, no strips!) for chlorine, pH, TA, CYA, and calcium hardness. Also, what type of pool (gunite, vinyl, plaster, etc), what size pump and type/size of filter you're using, as well as what ingredients you've put into the pool so far (ingredients, not just "shock"). Also, what is your regular chlorine source, and what was your CYA at closing last year?

Is the pressure on your filter rising as the pump is running? You said the water is cloudy--is it blue cloudy or green?

[Preston]

Chlorine:0
TCI:3
ALK:80
PH:7.2
Total Hardness:100

Vinyle

Filter: Sand & 2.7 Sq. FT

Ingredients: Shock (12ish bags), Alkilinity, Chlorine tablets

CYA: ? We didnt test this

Pump Pressure: 10

Cloudy is blue not green

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O and one more thing.... This was the first year we let the pool freeze over winter fully filled rather than half full then frozen. Could that have anything to do with the problem

[PoolDoc]

I doubt freezing had anything to do with it. More likely, it's the same thing we've been seeing so much of this season: bacterial bio-degradation of CYA (stabilizer) to ammonia, creating a HUGE algae demand.

Do you really have a 40K gallon pool? If so, we may need to look for a low cost source of chlorine; it can take 100+ ppm of chlorine to clean up the mess, and on your pool, that could be equal to 130 gallons of household bleach.

Here's where I'd recommend starting:

1. Get 4 quarts of polyquat, to keep your pool from becoming a total slime pit. (info here). If you can't find it locally, here's an Amazon link @ $18/qt:
Kem-Tek 60% polyquat

2. Do a bucket test for chlorine demand.

+ Get a CLEAN plastic bucket or garbage can, and fill it with 4 gallons of pool water (use a scale: 33 lbs + the weight of the bucket).
+ Dose with 1/8 cup of bleach, mix, and test with an OTO (yellow drops) kit (NOT: 'guess-strips' or DPD color match!!) You should see orange or brown.
+ Wait 30 minutes and retest: if there was high chlorine on the first test, and none on the 2nd test, you have confirmation of HIGH demand. If you see yellow, things aren't too bad.
+ Wait 1 hour, and retest. See if there's a difference.
+ If you've confirmed high chlorine demand, continue with 1/8 cup doses and 1 hour waiting periods until your chlorine level STAYS orange or brown.
+ Wait 4 hours, and see if there's change.
+ Let me know what you find.

[PoolDoc]

sorry. just moved your thread so you can respond.