Need help

[Wild Duk]

I can't get my free chlorine up....Its a 17000 gallon pool. The CYA was low, arounf 25, so I'm bringing that up, but last night I put in 2 1/2 pounds of shock, kept the pump and SWG on all night, tested this morning and the FC was about .5

The TC is still very high...

The water is very clear. Could there possibly be some type of algea eating the chlorine that it not visible?????

 

[PaulR]

Could be a "nascent bloom" where it hasn't gotten going enough to be visible. Have you been keeping your FC up properly? In any case the high CC means you need to shock. What kind of powder are you using? If it's dichlor that will help bring up the CYA. If it's cal-hypo then whether it's okay depends on where your CH is already.
--paulr

 

[Wild Duk]

I'm using dichlor to add chlorine and bring up my CYA, as well as stabliizer......Should I go ahead and shock with bleach, even though my CYA isn't at the appropriate level yet???

 

[PaulR]

Yes. Look up the shock level for CYA 25 and do that today; starting tomorrow shock according to your target CYA level. The CYA takes a while so don't bother testing it until next weekend; just assume it's where you want.
--paulr

 

[Wild Duk]

Ok thanks for the quick reply....So for CYA of 60, and a salt pool, it recomends a level of 24 for shock....Thats 6 gallons and 2 qts of bleach for a 17,200 gal, pool......Is that right, just dump it all in at a return jet????

 

[PaulR]

Today your CYA is 25, shock level is 12, with 6% bleach that's 3 gallons 1 quart (or, 3lb dichlor, which will also raise your CYA by 11). Pour bleach (or dissolved dichlor) slowly in front of a return jet. Leave the filter on 24/7.

Tomorrow you assume your CYA is 60, shock level becomes 24; see where your FC is and bring it up from there.
--paulr

 

[Wild Duk]

How soon after I shock the pool should I test for Chlorine???

 

[frustratedpoolmom]

Wait at least 30 minutes, but no later than 60 minutes, to confirm you reached your target.

 

[Wild Duk]

Well I didn't get a chance to test last night, but I did test it this morning and the FC was at .5 and the TC was at 4.5.

Do I shock it again now????

 

[DaveNJ]

I would say yes. Your CC is 4 and basically no FC. I would keep it at shock level until your CC is 0-.5 and FC level holds overnight.

 

[Lershac]

It helps to think of shocking not as a one time dumping in of bleach but as a process that may take a couple of days.

Bring your FC up to shock levels and then KEEP IT THERE through the frequent testing and adding of bleach, until your CC is 0.5 or less and the FC stays stable from say 9-10pm until just before sunrise. Then shocking is done.

 

[DaveNJ]

The attached link from Pool School describes the over night FC test.
pool-school/overnight_fc_test

 

[Wild Duk]

I added another 6 3/4 galoins of bleach...Tested again at 45 minutes and FC was at 5 CC was at 6......

Just keep at it with the bleach? Is this a normal situation if there is something in the water eating up your chlorine????

 

[frustratedpoolmom]

I think you possibly have an ammonia issue going on. What you are describing fits the pattern.

You can pick up an inexpensive ammonia test kit at a Pet shop, this will help give a vague idea of how much chlorine (ALOT) it will take to oxidize the ammonia (it will also rule ammonia out if it is just algae).

Also, try this test:

If you have been adding lots of chlorine and FC is always zero (or close), you can do a test to see how much chlorine it will take to be able to hold a FC level.

1) Put five gallons of pool water in a bucket.
2) Add 1 oz of 6% bleach
3) mix throughly
4) wait one hour
5) test the FC level
6) If FC is 10 or higher you are done. As long as FC is less than 10 repeat steps 2 through 6.
7) If FC is 10 or higher on the first round, repeat the entire test with fresh pool water and use teaspoons instead of oz of bleach.

Each oz of bleach is equal to 96 ppm of chlorine. Each teaspoon of bleach is equal to 16 ppm of chlorine.

This test is most useful when you have CC, ammonia, or fertilizer in the water. The results will not be accurate for baquacil, which reacts too slowly, and are only approximate for algae, since you can't safely add chlorine to the pool that quickly and with algae speed matters.

Regardless, the answer is plenty of chlorine. If you can get some of the strong stuff, rather than bleach, that would save you lugging a bunch of jugs.

 

[Wild Duk]

I do have lots of dogs that swim in the pool, would that account for the ammonia????I will go get an ammonia test kit today.... I have a Leslies store nearby, what should I use, their Power Powder Plus......Does that raise CYA???

 

[frustratedpoolmom]

I do have lots of dogs that swim in the pool, would that account for the ammonia????I will go get an ammonia test kit today.... I have a Leslies store nearby, what should I use, their Power Powder Plus......Does that raise CYA???

If FC gets too low for an unspecific time period - if certain bacteria are present, the CYA in the pool can be converted to ammonia.

Just straight Cyanuric Acid, at least 96% strength is a better buy, and then use 12.5% liquid chlorine if you can find it.

 

[PaulR]

I have a Leslies store nearby, what should I use, their Power Powder Plus......Does that raise CYA???

Power Powder Plus is cal-hypo, not dichlor. It does nothing to CYA (but will increase CH a bit).
--paulr

 

[Wild Duk]

I got a ammonia test kit, and tested almost none in the water, maybe .25 ppm if any.....I guess I will just keep bringing it up to shock level intil it holds FC....

 

[frustratedpoolmom]

Well that's good news. Keep shocking then

 

[Wild Duk]

Went to bed last night water was 22FC 1.5 CC
This morning its at 12 FC 2 CC.

I feel like this is a loosing battle.....I'm running out of reagent....