huge clorine demand

[sabres07]

Since i openned my pool in early May, I have been expeiencing a huge chlorine demand. I thought my testing reagents might be old and giving me bad results so all have been replaced. i stll have chlorine demand of 6-10 ppm each day. Water is crystal clear. I have kept the pool above shock level for 9 days now and overnite i still lost 4 ppm. What could be my problem?? Here are my latest numbers- FC 26.5. Ph 7.6. Cc 0.0. tA 110. Stabilizer 50. My FC was well over 30 last nite at 11 pm.

[sabres07]

Added info: I re-tested and FC was down to 18.5 which means I lost 15 ppm in less than 24 hours with no swimmers usimg pool. Water is crystal clear and I have held pool over shock level for 9 days. I need help!

[JimK]

Added info: I re-tested and FC was down to 18.5 which means I lost 15 ppm in less than 24 hours with no swimmers usimg pool. Water is crystal clear and I have held pool over shock level for 9 days. I need help!

Did you lose CYA over the winter? As I understand it, CYA can be eaten by certain bacteria over the winter and the resulting byproducts (sorry, I forget exactly what they are) create a huge CL demand in the spring. I've experienced this several times, although for seem reason it did not happen this past winter. If this is the case you will just have to keep at it with CL until all the byproducts are gone.

Hopefully someone more knowledgeable will chime in as well.

[BigDave]

I don't claim to be more knowlegeable but, I would expect to see high CC, low FC and no (or severely depleted) CYA if sabres07's pool had experienced the CYA eating, ammonia excreting bacteria.

Perhaps it's bio-load, although I'd expect to see some CC.
Is there alot of pollen? Maybe there's lots of biological material in the filter being consumed by the chlorine not but reading elevated CC because the hich FC in the pool is doing away with the CC before it can be read. Just a Wild Antelope Guess. How's the filter?

[JimK]

I don't claim to be more knowlegeable but, I would expect to see high CC, low FC and no (or severely depleted) CYA if sabres07's pool had experienced the CYA eating, ammonia excreting bacteria.

Perhaps it's bio-load, although I'd expect to see some CC.
Is there alot of pollen? Maybe there's lots of biological material in the filter being consumed by the chlorine not but reading elevated CC because the hich FC in the pool is doing away with the CC before it can be read. Just a Wild Antelope Guess. How's the filter?

Ah, I missed that CC is measuring 0. Thanks for catching that.

[sabres07]

A few days ago, I thought maybe something was living in my filter cartridge, so I removed that and continued with my program of keeping the pool at shock level. Still no change. Also, I thought it might be the amonia issue due to degraded CYA because I had that problem last year. I have a 40-50 CYA reading this spring which is only down slightly from closing last fall. There was a lot of pollen a week ago, but has since not been an issue.

My plan is to continue with holding above shock, but this is getting ridiculous!! Like I said, the water is crystal clear and inviting. No visible signs of any issue other than my crazy chlorine readings....