Why all the dichlor hate?

thefloatqueen

Bronze Supporter
Dec 24, 2018
665
Columbus, OH
So between heavy rains, splash out, evaporation and having to add fill water, etc., my CYA dropped from 50 to 30. With all the sun and hot temperatures lately, I noticed I’ve been adding A LOT of LC each day. No algae at all, always keep my FC well above the minimum required and vacuum and brush regularly. This past week, I have been using dichlor to try to get my CYA up while also using it to chlorinate my pool. YES, I know dichlor has a higher amount of CYA than the trichlor pucks. I am ONLY using it because
A: I already have a bucket of it taking up space from when my mom bought it for me last summer and
B. I’ve been trying to steadily increase my CYA (I’ve been testing and using PoolMath.)

So I guess my question is, why does dichlor get so much hate on the forum but responsible use of trichlor pucks do not? Both are stabilized forms of chlorine. Yes, I understand dichlor has more of it which is why when my CYA was in the 40-50 range, I would NEVER use it (or trichlor tablets). For this type of use, I don’t see anything wrong with it. I normally strictly only use bleach/LC. Yesterday I finally got fed up with how sloooowly the dichlor was increasing my CYA (very small difference....the dot would just disappear a little sooner after the 30 marker than previously) and added regular stabilizer via the “sock method” and am testing my CYA this morning. I will now go back to ONLY using liquid chlorine. Is dichlor really that bad? Also, how long after adding CYA (whether through dichlor granules or stabilizer) can I test for the most accurate results? I did the sock method yesterday around 8 pm (sunset). Hoping it will be at my goal of 40 today. Thanks in advance!! :)

- The CYA-Deprived Float Queen
 
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IceShadow

Gold Supporter
TFP Guide
Jun 8, 2019
2,177
Milwaukee, WI
Dichlor is fine if you know what it’s adding in CYA and account for it. We don’t recommend it because most people don’t have the need for more CYA when they come here, but people who account for the CYA shouldn’t have issues using it.

I am unsure how long the CYA will take to measure, but I would say after 48 hours it should be safe.
 
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thefloatqueen

Bronze Supporter
Dec 24, 2018
665
Columbus, OH
Dichlor is fine if you know what it’s adding in CYA and account for it. We don’t recommend it because most people don’t have the need for more CYA when they come here, but people who account for the CYA shouldn’t have issues using it.

I am unsure how long the CYA will take to measure, but I would say after 48 hours it should be safe.
Thank you!! The instructions on the back of the stabilizer I used says to run the pump for 48 hours after adding it (it says to add it to the skimmer but I used the sock method.) I guess I’ll test CYA tomorrow then so I don’t waste the testing reagent.
 
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thefloatqueen

Bronze Supporter
Dec 24, 2018
665
Columbus, OH
It’s supposed to be cooler today and tomorrow so I figured last night would be a good time to add the stabilizer since no one will be in the pool for a couple days since the water is too cold and I do not have a heater. How much FC loss on a sunny 75+ degree day is normal for a crystal clear pool with no CCs?
 

thefloatqueen

Bronze Supporter
Dec 24, 2018
665
Columbus, OH
If you have no other organics eating and your CYA is at an appropriate level for the climate, 2-4ppm loss of FC in a day is typical.
Okay I feel a lot better then. I have been losing around 3.5-4ppm a day. I always keep my FC on the higher end of the recommended range to avoid it dropping below the minimum. Haven’t had any issues with that but I have been going through more bleach lately for sure.
 

thefloatqueen

Bronze Supporter
Dec 24, 2018
665
Columbus, OH
More CYA should help. Don’t go above 50ppm because it would make it difficult to test your pH at standard needed FC levels.
Oh I definitely wouldn’t go higher than 50! My goal is 40. After adding the stabilizer last night, I’m done with the dichlor and back to bleach only. I only used dichlor to try to get the CYA up before giving up and just adding stabilizer instead.
 
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wogster

In The Industry
Apr 30, 2018
158
Toronto, Ontario, Canada
The big problem with Dichlor, is that it adds CYA and chlorine, the chlorine goes away fairly quickly, the CYA goes away very slowly. In pools that are located in places that don't close for the winter, this means that the CYA can build up. However where I am, the pool level is lowered quite a bit, and then the winter cover is put on. In the spring the cover is drained, and then the pool is refilled. So whatever CYA was in the water, has been reduced, by at least half, it could be even less. The use of Dichlor or Trichlor in this case, can be used to restore that CYA to some degree. It needs to be monitored though, if you are shooting for 45, and it's already at 43, you probably don't want to be tossing in a large amount of dichlor. However if the winter has left it around 15, and your adding 5PPM of chlorine, then adding 5PPM of CYA at the same time, will be fine....
 
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