Re: Is CYA the same as Trichloro-s-Triazinetrione tablest?
Tri-chlor is chlorine that release CYA as it is used. But CYA, called also stabilizer, conditioner or Cyanuric Acid can be purchased as a seperate chemical.
Tri-Chlor is chlorine in the form of tablets (or sometimes powder) that goes in automatic chlorinators or floaters. When you need CYA added to your water, they can be a good way to add it, because as they erode they keep a fairly constant level of chlorine in your water. But Tri-Chlor has another bug/feature: It's highly acidic and tends to drive pH down. If pH is low, it's not necessarily a good idea to use it, although you can compensate by adding Borax to raise pH.
However, if your chlorine levels are good and you are using bleach or liquid chlorine to maintain them, you can just use CYA powder by itself.
But many people run into trouble by using Tri-Chlor tabs in a chlorinator all summer without watching CYA levels. Their CYA shoots up and despite having what they THINK is adequate chlorine, they get an algae bloom. That's when we say STOP DON'T USE TRI-CHLOR ANYMORE!
So, if pH is low and CYA is at your target level (another discussion for another thread) or high, don't use Tri-chlor.
If, however, you have no CYA and your pH is trending high then Tri-chlor may be ideal. This comes up when people have new gunite/shotcrete/plaster or tile pools that are curing, and, as they cure they drive up pH. Being new water, they also need CYA. THEN Tri-Chlor is good to use.
There's a powder called Di-Chlor that's very similar to Tri-Chlor. It's not as acid but adds even more CYA than Tri-Chlor. Same rules apply.
Cal-Hypo, the third powder, adds calcium, which may or may not be a problem...if it gets too high it's a problem.
Best is Bleach/ Liquid Chlorine. No side effects to worry about!
16'x40' rectangle 19K gal AG vinyl pool; ; Hayward T210 sand filter and 2 Speed Superpump 1hp pump; Solar heated. Test kit: PS 233; PF:6.3; Autopilot SWCG