Pool Math Question - How to enter this product

michaelr0

Active member
Mar 26, 2018
31
Omaha, NE
Before I got to this site and learned about liquid chlorine, I went to Walmart and bought a variety of different products thinking I will be using them at some point. I bought 6 packs of this product. It has 43.47% of Trichloro-S-Triazinetrione and 56.53% Other. I only see Trichlor listed in Pool Math. Is there a way to enter this product or what do I choose to approximate it? There is a very similar product which has trichlor 53.5% / other 46.5%. This is why I expected to be able to select a percentage like it is available with cal-hypo.

My CYA is very low ~20, so I might as well use some of these products and get rid of them.
 

michaelr0

Active member
Mar 26, 2018
31
Omaha, NE
Thinking about this: my package contains 13.4 oz. The active ingredient is 43.47% so I assume I enter Trichlor and use 5.8oz in Pool Math? If that's the case, I definitely got jibbed. The product I purchased was $2.97 for 13.4oz at 43%, the second is $2.49 for 16oz at 54%. Product one is $0.51/oz, product two is 0.29/oz.
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
22,396
Laughlin, NV
Trichlor is trichlor. Just enter the weight of what you are adding into Poolmath.

Only Calcium Hypochlorite and Sodium Hypochlorite come in % concentrations when talking about chlorine products.
 

Donldson

TFP Expert
LifeTime Supporter
In The Industry
Jun 12, 2009
3,928
NW Ohio
The reason you don't see a percentage is because trichlor is typically used in a pure puck form. When it is sold as shock they add sodium bicarbonate to counter the extreme acidity of the product. You'll just have to do the math yourself to use it, multiply the amount you are using by 0.4347 to figure out how much trichlor you are actually adding.

For the record, that's a pretty bad value. One bag of that will raise your FC by only about 2 ppm. For comparison a gallon of 10% will give you 5 ppm and a pound of 65% cal-hypo will raise it by 4. If you are going to counter about needing CYA, it will only raise it by 1.2 ppm so that's hardly a consideration. Also if your TA is not low you are going to be dealing with that going up. I wouldn't say you got jibbed, the information was all there for you when you purchased it.

EDIT: I type slow sometimes, but yes, you got the math correct. 5.8 ounces of trichlor per bag.
 

michaelr0

Active member
Mar 26, 2018
31
Omaha, NE
Use liquid chlorine.
Understood but I have 4 more bags of the trichlor shock that need to go. I also bought 4 bags of a 56% cal-hypo shock product that I want to use before the season is over. Now that I understand water chemistry better, I am going to simplify my chemical stock.

After "smarting up", I went back to Walmart and secured 10 gallons of 10% liquid chlorine to be sure to have enough for the rest of the seasons. Naturally, a day later I learned that Menards sells 12.5% for less 15% than Walmart. Live and learn!

Going up by about 2ppm is exactly what happened. My before FC was 1.6 and the after 6.2. Considering that I also had to get the brush out to stir up the particles that sunk to the bottom, it is a bad deal all around.