Dichlor Confusion. 1 tbsp = ?

[Hub]

I'm in the process of adding dichlor to new water for 4 days to get my CYA ideally up to 40. I intend to run a test for CYA after I have added what should be the right amount to get to 40.

My confusion is in the amount of dichlor that I am adding. Pool Calculator says I need 7 ounces of dichlor to get to about 40 CYA in my little pool. I am using a tablespoon to measure and by volume am going by 2 tbsp = 1.0 oz. Something is telling me I should be going be weight and not volume, but that's likely not a huge difference. Something else is telling me I'm over complicating this.

So how much dichlor is a tablespoon?

Thanks.

 

[Richard320]

So how much dichlor is a tablespoon?

Thanks.

1/16 of a cup. Or 1/2 fluid ounce (that's volume)

If you want 7 oz by volume, 14 level tablespoons. And don;t tell the wife you're using her utensils. Be sure to rinse it well, too.

 

[linen]

Your 1500 gallon pool needs 16 oz by weight or 15 oz by volume of dichlor to raise cya by 40 ppm. I used the "effects of adding chemicals" section of the poolcalculator to get this (it gives weight).

 

[BoDarville]

Pool Calculator says I need 7 ounces of dichlor to get to about 40 CYA in my little pool.

Are you starting from a CYA of zero? Also, what are your current FC and pH levels?

Using the Pool Calculator's "Effects of adding chemicals" section, adding 7 oz of dichlor in a 1,500 gallon pool will raise the CYA by 18 ppm, but it will also raise FC by 19 ppm and lower pH by an estimated 0.74. That's the issue with using dichlor instead of a dedicated Stabilizer product solely to raise CYA. Dichlor moves several other parameters in addition to CYA. As a result, these other parameters may be pushed outside of the recommended levels.

 

[Hub]

Glad I posted what I was afraid was a dumb question! Using the pool calculator I had just set CYA at 0 and desired at 40 and it told me I needed 6.7 oz of "stabilizer." I now see the part at the bottom about specifically what dichlor will do. Very interesting.

I need to change my sig, but the pool actually holds 1200 gallons where I fill to and not 1500.

And yes, totally busted on using the tablespoon from the kitchen. Thank you all so very much for saving me here. I'll do some proper testing, but the lowering PH and the raising of FC should both be fine as my PH started out at 8 and FC at 0. Plus last year I had to add acid with some regularity to keep the PH down. I'll just use the dichlor to chlorinate until the CYA is right and then get a proper CYA source for next year. Thanks again!