Chlorine levels not increasing

[SuperMiguel]

Good morning i have a week old pool, that wont hold chlorine, here are my readings from yesterday:

FC -> 0
pH -> 8.0
TA -> 50
CH -> 250
CYA -> 0

Added about 1/2 gallon of acid, reading from today shows around 7.0 I also added a gallon of liquid chlorine yesterday (Sodium Hypo 10.5%) and still FC sitting at 0 this morning, i also have 2 chlorine tablets inside my skimmer as instructed by PB.

Is there anything else i need to do?

 

[mknauss]

The half life of FC in a pool without CYA in it is 50 minutes with sun shining on the pool surface.

You need to add CYA.

Remove the tablets from the skimmer. Use a floater whenever using tablets.

 

[ccbill]

Zero CYA will be at least part of the problem. Are you using a FAS-DPD test kit to measure your FC? Maybe you already have algae growing, have you done an Overnight Chlorine Loss Test?

 

[SuperMiguel]

The half life of FC in a pool without CYA in it is 50 minutes with sun shining on the pool surface.

You need to add CYA.

Remove the tablets from the skimmer. Use a floater whenever using tablets.

ok ill move the tablets to a floater, and ill go buy some CYA.

 

[SuperMiguel]

Zero CYA will be at least part of the problem. Are you using a FAS-DPD test kit to measure your FC? Maybe you already have algae growing, have you done an Overnight Chlorine Loss Test?

Im using the TF kits.

 

[VinnyinNJ]

When did you add the chlorine? As mknauss said sunlight eats up chlorine. You need to raise the CYA and the best test to see if it's algae or sunlight is to put a jug of bleach in the pool at dusk/night when there's no sunlight hitting the pool, measure after 20 minutes and then next morning measure again before the sun hits the pool. If the FC is 0 then you have an algae eating up the chlorine. BTW, you need a good test kit for accurately analyzing your water.

 

[SuperMiguel]

When i add CYA, should i add chlorine as well? Or I need to wait some time before adding more liquid chlorine, it does have 2 tablets, now on a floater as suggested

 

[VinnyinNJ]

I used to add CYA right into the skimmer basket and let the filter do it's thing. I have seen that the preferred method is the sock method which basically almost the same thing - fill a sock with stabilizer, put/hang the sock in the skimmer and let it dissolve, this is better for your pumps impeller IMO!

I would add bleach/liquid pool chlorine about an arms length in front of the return. I don't think there will be any reaction with the chemicals.

 

[IceShadow]

There are a couple of issues with adding CYA directly to the skimmer.

1) CYA can get a little soft/mushy as it starts getting wet, and this can cause a clog in your pipes. We've seen it before - search the forums. Not fun to deal with.
2) If it does get through your pipes it has to sit in your filter for a while to dissolve. Most instructions say not to backwash/clean filters for a week (!) while letting the CYA dissolved.

If you put it in a sock and hang it in front of the return jet, it'll dissolve without these dangers. A little squeezing can help it move along.

 

[SuperMiguel]

Just wanted to double check if you all agree with the NPT startup procedure and numbers, based on this link: National Plasters Council Procedure | NPT Pool Finishes | NPTpool.com here are the numbers they want

pH -> 7.2 - 7.6
TA -> 80
CH -> 200 max
FC -> 1.5 - 3
CYA -> 30 - 50

Here are my results from this morning:

pH -> 7.8
TA -> 40
CH -> 275
FC -> 0.5
CYA -> 30

So i guess i need a bit of Acid to lower my pH, a bit of baking soda to increase TA, liquid chlorine to increase my FC, maybe a tiny bit of CYA to increase my CYA to 40..... Now what do i do about my CH, mine is currently at 275 (Pool math recommends 350) but NPT website says to keep it at 200? So i need to lower it or increase it?

 

[SuperMiguel]

bump

 

[mknauss]

The focus of the first 30 days of new plaster should be to keep the CSI between 0 and 0.5, and the FC at 3 ppm with a CYA of 30.

 

[SuperMiguel]

The focus of the first 30 days of new plaster should be to keep the CSI between 0 and 0.5, and the FC at 3 ppm with a CYA of 30.

CSI?

 

[mknauss]

Calculation in PoolMath. Plaster companies sometimes use LSI. Nearly the same thing.