CyA.. How Much, How Often to Add, Typically?

Sammy2

Well-known member
Aug 30, 2016
378
Riverside, CA
#1
I am thinking of putting 7 lbs on a 6 month Subscribe and Save Subscription with amazon.

https://www.amazon.com/gp/product/B00IZOE4HI/ref=ox_sc_act_title_1?ie=UTF8&psc=1&smid=ATVPDKIKX0DER

It can be canceled at any time for any reason and this seems to be just what the doctor ordered. With the long hot summer just ahead and our pool in full sun sunrise to sunset with the back yard oriented nearly due south and the only blockage is from the neighbor's house when the sun is almost set I think I'll be needing more of it this summer to keep things in check. Does it get consumed or am I ordering too much? I can go 4 pounds too but it ins't quite as cost effective.

TIA
 

fields_g

Well-known member
Dec 25, 2014
87
Rockville, MD
#3
Your entire pool needs 11 lbs to go from 0-80ppm (high end of suggested with a SWG). You only need to add cya as water is added. I would think a single 7lb packet would last you a while as long as it is for maintaining CYA level.
 

Sammy2

Well-known member
Aug 30, 2016
378
Riverside, CA
#4
I'm in process of adding CyA right now to bring it up from a low lrvel.

Results from poollogger.com

FC: 13
CC: 0
PH: 7.2
TA: 110
CH: 500
CYA: 50
Temp: 71
Salt: 3300

Sent from my SM-G930P using Tapatalk
 

Sammy2

Well-known member
Aug 30, 2016
378
Riverside, CA
#5
I normally add several hundred gallons of water a month in the summer so it gets diluted and needs more CyA and MA going forward.

Sent from my SM-G930P using Tapatalk
 

jblizzle

Mod Squad
TFP Expert
LifeTime Supporter
May 19, 2010
41,197
Tucson, AZ
#6
Cya does not evaporate, if the water you are adding is to counter evaporation, then there is no need to add more CYA.

If the CYA is dropping, perhaps you have a leak. Or if you get enough rain that causes overflow, that could lower it too.
 

domct203

Bronze Supporter
LifeTime Supporter
TFP Guide
Jun 3, 2015
3,959
CT
#9
Due to splash out and a small leak somewhere.

Sent from my SM-G930P using Tapatalk
That would fall into the 'water exchange' category.

Typically speaking, I add CYA once per season, and only 10-20ppm worth.
 

prs

Silver Supporter
LifeTime Supporter
Sep 8, 2014
155
Bakersfield, CA
#13
I live in Bakersfield and during the summer we have endless days of 90-100°F without a cloud in the sky. I have to add 28 ozs of CYA once or twice during this period to maintain 90 ppm. I know the loss is from degradation by the sun because I see no CYA loss at all from October thru May.

Pool water temp may also have an impact on CYA degradation, my water temp is well into the 80s when I experience the highest rate of loss.
 

jv92red

LifeTime Supporter
Mar 7, 2013
117
SoCal
#15
Just checked my CYA last week and found out that I was completely out - kept filling up the test tube with the solution and the black dot never went away! I was at about 70ppm at the end of last summer so not sure what happened over the winter. My pool does not have a leak and my borate level measured about the same as last summer at 50ppm so there is no leak. We did have plenty of rain this winter which cause some drain off so now not sure why my borate level stayed the same over the winter unless my reading last year was higher than I realized (those LaMotte strips are a pain to gauge)
 

prs

Silver Supporter
LifeTime Supporter
Sep 8, 2014
155
Bakersfield, CA
#17
Do you add water? I think that maybe it is more due to that than due to UV degradation but I am probably wrong.
If CYA didn't degrade the only way you could lose it would be with any water removed from the pool. Water losses by evaporation wouldn't change the amount of CYA left in the pool.

To answer your question, yes I do add water. When it's 100°F with very low humidity my water loss by evaporation is huge. :sun: