Formula for raising CYA with trichlor

[eroc37]

25,000 gal vinyl pool.

bought house and continued previous owners routine of adding Trichlor to feeder every week and using simple test kit for CC and PH. Last spring pool turned green and even though CC levels were ok, no amount of shock or algecide would turn water clear.

Through much online reading i found this site and through the use of the proper test kit found my CYA was over 100!

Serious shock with Bleach finally solved the green water and this past winter i drained as much of the pool as i felt comfortable and refilled. Pool is crystal clear and i can see the slight staining caused by the algacide i used. I'll tackle that with ascorbic acid later. just happy to be able to see the bottom!

Now my :

PH is 7.5
TA is 50
CYA <20

I have some Trichlor left from before (3 Inch tabs) and i am wondering if there is a formula for the increase in the level of CYA per ounce of Trichlor for a 25,000 gallon pool.

i don't want to buy Stabilizer if i can safely add CYA with the trichlor, but i am sure you can understand my hesitation in adding the evil tablets to the feeder.

 

[duraleigh]

For as much CYA as you need to add, I wouldn't suggest you do it with pucks.....it'll take forever and you'll have to constantly test and worry over it (or forget about it) before you ever get it right.

Keep the pucks you have left for a vacation or something. Buy enough stabilizer to get your pool to around 40-50ppm.

You don't list how much chlorine is in your pool......there's a good chance it may be quite low since you have no CYA.

 

[frustratedpoolmom]

HI there
Dave is right, trichlor is not what you want - and since it led to your troubles in the first place, you want to save it for vacations, etc. and not use it for everyday purposes or raising CYA.

First, your TA is a bit low - purchase some Baking Soda to raise the TA. If you learn how to use the Pool Calculator (see the link in mine and Dave's sig) it will tell you how much to add to get your TA up to at least 70. You can also use the calculator to determine how much CYA to add. We can help you figure it out, there is also an article in Pool School that gives you the instructions for it.

As long as you don't use the pucks very often and you avoid granular "shock" bags that contain "Dichlor" (which contains CYA) you're CYA level will stay stable and you won't have to worry about it much at all.

If the staining is from using Copper Algaecide, the AA treatment probably won't do any good.

Hope this helps.

 

[eroc37]

Yeah... my chlorine IS really low. i was about to add liquid bleach but i thought maybe i would ask about the trichlor. i'll get real stabilizer next week. Thanks for affirmation on the proper CYA levels.

I know the TA is low... I am familiar with the pool calculator and will add baking soda when i add chlorine tomorrow. Should i do it in two steps? Half now... retest and half in a couple of days?

I don't actually know what the staining is from. it is brown and noticable on the white stairs, some faint staining in the deep end, and the outside of the strainer at the water line. It happened over the winter, (winter before last) before i knew what was going on. the Trichlor kept my PH very high and i constantly added sodium bicarb to adjust, not knowing what it would do to TA. I didn't even know there was a 'TA'. By the time i found this site my TA and CYA were off the charts, my pool was green and nothing... not even algaecide seemd to help.

I am VERY thankful for all the help and good advice this site offers!

 

[frustratedpoolmom]

Glad to help.
Test the staining with a Vitamin C tablet. If the AA treatment will work, the Vit C will make the stain vanish almost immediately. If the Vit C tablet does nothing, don't waste your time. Let us know what happens.

Just go ahead and add the proper amount of Baking Soda for the TA. IF you want confirmation, just post it and we'll tell you if you are correct. Dissolve it in a bucket of water and pour it in front of the skimmer, leave the pump running, brush the pool if you can. Test it in the morning.