CYA reading at 0

[mn_]

I tested my CYA when pool opened and it was 0. I added some dry stabilizer and it got up to 50. Now a month later, it's reading at 0 again, how can that be? We've gotten a lot of rain and backwashed somewhat but I don't know why it's reading at 0 still. I was under the impression it does not change through the season? should I add some more? I've tested it 3 times now. I'm using Taylor test kit. Pool is clear and I know I have to add more chlorine because it keeps going down so fast food to CYA being low, rest of the numbers are below:

CC: 0.2
FC: 0.2
TA: 140
CH: 250
pH: 7.8
CYA: 0

 

[mknauss]

Prior to adding any CYA, please raise your FC in the water using enough liquid chlorine to get to 10 ppm using PoolMath. Circulate the pool for 15 minutes. Test FC and CC. Report the results here.

 

[PoolGate]

Go to an aquarium shop and get an ammonia test. You may have ammonia. Report back if you do.

 

[IceShadow]

Prior to adding any CYA, please raise your FC in the water using enough liquid chlorine to get to 10 ppm using PoolMath. Circulate the pool for 15 minutes. Test FC and CC. Report the results here.

Go to an aquarium shop and get an ammonia test. You may have ammonia. Report back if you do.

To clarify: there is a bacteria that will eat CYA and turn it into ammonia. Both of these are ways to test for the ammonia - if the FC is gone and CCs are high 15 mins after adding liquid chlorine, it shows ammonia.

 

[tolian21]

What’s the water temperatures? When water is really cold the readings could be a bit off

 

[mn_]

Prior to adding any CYA, please raise your FC in the water using enough liquid chlorine to get to 10 ppm using PoolMath. Circulate the pool for 15 minutes. Test FC and CC. Report the results here.

I raised the FC = 10.8 & CC = 0.2 and it stayed there for about 30+ minutes, can I throw in the CYA now?

 

[mknauss]

I raised the FC = 10.8 & CC = 0.2 and it stayed there for about 30+ minutes, can I throw in the CYA now?

Yes.