Cyanuric acid missing

[smileitsachoice]

I have started up my pool for the spring. Opened to a green mess. After about 70 gals of bleach (30k gal + vinyl in ground), I have apparently held chlorine overnight. My question is I tested at zero cya at opening (I am sure it was eaten by bact.). Normally I keep at 50+ ppm due to living in the deep south. I have started adding cya with 2 socks with 3 lbs each at each skimmer entrance. My question is (finally I know) Is it ok to add bleach in the deep end with the cya at the sides? Oh yea ph is 8 to 8.5, alk. is 90. Thanks, been using the bbb method for 3 seasons and it was the best thing I have every done for my pool.

[aylad]

Hi, glad to see you back!! Yes, it's fine to add bleach at the deep end with the CYA at the sides, just don't put them into direct contact with each other. You need to get the pH down below 8, though. Low chlorine, low CYA and high pH are ideal conditions to use trichlor, if you're tired of hauling bleach

[smileitsachoice]

yes good idea, Everybody at Sams probably thinks I am building bombs or something

[smileitsachoice]

Janet,
I just checked my ph and is was probably over 8. I went ahead and added some acid, how long do you think I need to wait to retest. Also I was going to retest about dark and add bleach to get me to about 8 or 9 ppm. Does this seem like a good idea.

[Watermom]

I'm not Janet but ............You can retest pH after 3 hours or so. Give the acid plenty of time to mix in well. Yes to adding more bleach this evening.

[smileitsachoice]

Watermom,
Sorry I thought Janet had answered my first question but thanks for the reply. Will retest tonight.
Thanks

[Watermom]

It was Janet. But, she and I bounce in and out of the threads without worrying about 'whose' thread it is.

[PoolDoc]

Just want to confirm:

+ 30K gal pool
+ 50+ CYA in fall
+ 0 CYA when opened
+ 70 gallons of 6% bleach to achieve chlorine retention overnight (140 ppm chlorine dose!)

Are those statements correct?

[chem geek]

Sounds like bacterial conversion of CYA into ammonia as happened to me and that I describe in this thread (this post has a summary of chlorine usage before I got a reading and is described technically in this post). For every 10 ppm CYA degraded it would take at least 25 ppm and possibly 32 ppm chlorine to get rid of it. So 50 ppm CYA could take 125-160 ppm chlorine and that's not counting what is needed to get rid of any algae.

The best way to minimize the likelihood of this happening or of opening a pool to algae is to close the pool when the water is cold (below 60ºF and preferably below 50ºF) and to open the pool early before it warms up (so before it hits 50ºF or 60ºF). Of course, if one can maintain chlorine in the pool over the winter, that will work but isn't viable for pools that are closed due to freezing.

[smileitsachoice]

Ben
I would be happy to give you the exact numbers. First it has been 14 days this morning since I started my pump for the season. I closed in later November when it was in the 40's. I took fc to shock level @ 15ppm, ph @ 7.8, ta @ 100, and cya 50ppm. I let it circulate 1 day and pulled pump. I do not cover pool just winterize and leave uncovered. Living in the deep south this year we had almost no winter with temp at times in the 80's and easily the 60's at night. When I opened 2 weeks ago I had 0 cya, 0 fc, and ph was high at well over 8ppm. I have added to date 72.5 gals of 6% bleach, 9 lbs cya, and 12 pounds of baking soda, oh yea 120 lbs of salt ( I do not have a swg but run about 2000 ppm salt for feel). I just tested about 15 minutes ago and here are the numbers. fc=9, cc=0, ph=7.3, cya=40ppm, ta=120, and salt=2290. It is a 20*40 vinyl inground pool with a sand filter. If my math is right it should be in the 30 to 32000 gal range. This is the third season I have used your method and it is wonderful. My maintenance last year for example was about a 1.5 gals of bleach a day, and that was all. What is your opinion of swg's. I have no problem with adding bleach but if there is something a little more maintenance free I am all about it. I just have not been able to justify $1000 for a swg. Is the money savings and time savings really there? My pool is pretty easy to maintain (once I do my due work for a couple of weeks early in the year). It cost me about 40 gals of bleach a month or about $85 dollars. And time wise less than 2 hrs a week including testing and adding bleach. Any input would be appreciated. Thanks again