It's muriatic. I would add chlorine only at start up & acid only when it's needed. Your supplier can show you how to check the pH & determine when one or the other is needed.
Should chlorine tablets be used in place of stabilizer chlorine tablets so the cyanuric acid don't get to high?
Chlorine is effected by sun, air, temp and bather load. You should check first to see that your stabalizer (cyanuric acid) level is ok, 30-50 ppm. That will help chlorine stay in water.
Use stabilized chlorine only so long as stabilizer level (cyanuric acid level) in pool is within the recommended range of 50-80ppm.
Assuming no other complaints you would only need to change water to lower the total dissolved solids level or cyanuric acid level. TDS should be below 500ppm and cyanuric acid ~50 ppm.
Chlorine level in an 18' above ground pool should be between 2 and 4.
Chlorine stabilizer, also known as cyanuric acid, is slow to dissolve in water because it is a large molecule that requires time to break down and disperse. It should be pre-dissolved in a bucket of water before adding it to the pool to help it dissolve more easily and prevent clumping.
manual
If you are getting a low reading of chlorine in your above ground pool, you should add the appropriate amount of chlorine to get it back to the correct level. This is important to keep your pool running at maximum abilities.
The constant use of small 1" , large 3" jumbo chlorine tabs and granular chlorine. they all have cyanurics acid in the compound mix. Best to switch to liquid for a while ( a month of so). The high levels of cyanurics will eventually drop as water evaporates and you add fill water. High levels of cyanuric acid or conditioner would be considered to be in excess of 100 ppm. You could also do a partial drain of the pool and refill to reduce the CYA faster. In the future you might consider alternating between liquid 12% chlorine and tabs. Note: 1" tabs dissolve faster. HTH granular and tabs I believe do not contain conditioner but then it is a lesser grade of chlorine - see percentage values on label.
Chlorine is taken up by biomaterials for one. that is the more dirt there is in the pool even stuff you cant see the more chlorine seems to disapear. the sun and the activitys of swimmers also have a big effect on chlorine consumotion. to hold onto the chlorine longer, Conditioner or Cyanuric Acid Levels should be kept up to about 80ppm, Low conditioner levels will lead to a lot of the chlorine in the water being burned of without it being utilized.
Before adding stabilizer (cyanuric acid) to a pool, the pH level should ideally be between 7.2 and 7.8, and the chlorine reading should be at or near the recommended level of 1-3 ppm for free chlorine. It’s important to ensure these parameters are balanced because high or low pH can affect the efficacy of the stabilizer and chlorine. Adjusting these levels first will help maintain optimal water chemistry and improve overall pool sanitation.
Manual Startup. Use services.msc in command prompt to set the startup.