Stabilized vrs liquid

[Walter2050]

Having a discussion with a co work . He stated that trichlor will last longer than liquid even if the pool already has the right amount of cya in the pool . So in theory if you add 5ppm of liquid and 5ppm of trichlor in a pool that already has stabilizer the liquid will disappear faster ?

 

[Donldson]

Your coworker is wrong. Possibly repeating something told to him by the person selling him pucks. Once it hits the water chlorine is chlorine.

 

[JoyfulNoise]

This is what we call being correct in the details but wrong in the big picture.

Yes, depending on where you are on the CYA curve and how much trichlor (or Dichlor) you add, the chlorine added by the stabilized chemical might last a tiny bit longer because the additional CYA drops the overall concentration of HOCl and OCl- … but who cares if it lasts longer … You’ve now also lowered the active chlorine concentration which makes your water less sanitary. So any marginal gain you might make in keeping chlorine levels around longer could be offset by a greater chance of the water becoming unsanitary.

Using liquid chlorine and a constant CYA level allows you to target the correct FC/CYA ratio which is what matters. Adding a chemical that raises both makes maintaining that ratio a moving target. And that is what leads to a green pool.

Your coworker clearly doesn’t understand how chlorine sanitation works or why the FC/CYA ratio is important. He’s missing critical facts which is why his idea sounds right but is totally wrong.