Frequency of Cal-Hypo with Stabilizer


New member
Jan 16, 2021
Hello I have a few questions as a new pool owner.

I have a 65000 liter plaster pool we just installed last month. Acrylic painted. I added about 30ppm of cyanuric acid by accident through the skimmer with circulation mode and saw all the granules go down to the bottom of the pool. I attempted to vacuum a day later with filter mode back on to capture them into my filter for slow dissolving. Hopefully that will be okay.

Secondly, according to my cal-hypo 65 instructions, it says to add 30 grams of chlorine for every 10,000 liters everyday for unstabilized pools, but only 15 grams /10000 liters every other day for stabilized pools. Before adding my stabilizer I was doing the first in the evening but by the morning when I tested there was barely any residual chlorine left. I'm hoping by adding the stabilizer that I will only need to manually add the chlorine every other day but unsure how long to wait for results. I added the stabilizer about 5 days ago and run my pump 6 hours a day, haven't backwashed yet. Thanks!

Texas Splash

Mod Squad
TFP Expert
LifeTime Supporter
Welcome to TFP! :wave: Your stabilizer should be okay as long as you got it vacuumed back up into the filter,. Probably just took longer to dissolve. Next time ask us about the sock-soaking method. :)

For the cal-hypo, I suspect your FC and CYA aren't ideally balanced as you can see on our FC/CYA Chart. Follow the balance on that chart for optimal results in preventing algae. You may know cal-hypo will increase CH quickly, so be careful. If that's all you have in your area, there's not much you can do. If you have liquid chlorine or regular bleach, that would be a better option.

See the link below for more help, and thanks for posting.



Gold Supporter
Bronze Supporter
Jul 17, 2019
Prosper, TX (DFW)
Do you have a good source for liquid chlorine or bleach in Rwanda? That and a salt water chlorine generator are the best forms of long term chlorination. Cal-hypo adds calcium which can lead to scaling long term. Other solid chlorine products also add extra ingredients including CYA that can also lead to problems down the road if they get above the recommended levels.