Chlorine Consumption Rate

I have been trying to figure out an appropriate bleach dosing schedule (6%) for my 27,000 gallon inground in Western PA.

I have been adding 3/4 gallon per day around 7 pm = 3-4 large jugs per week and cannot seem to keep the level above 0.5 ppm.

I think I have to go to 1 jug = 1.4 gallon Chlorox = 3 ppm per day.

1. Does this sound right? Seems like a lot of chlorine to me.

2. Is there a way to get non stabilized chlorine tablets? I dont like trichlor because the pucks screw up my ph and cya. I manage the alk increase from bleach by aerating.


FC .5
CC .5
TC .5
pH 7.2
alk 120
cya 40
Temp 84.

27000 gal pool. Solar cover used every night and about 3 days per week.

Sounds to me like you have two things working against you....first of all, with a CYA of 40, you want to maintain a MINIMUM of 3 ppm of chlorine, so when you add bleach, you need to add more than the minimum so that at the end of the day you still have the 3 ppm left over. Actually, 2-3 ppm chlorine loss daily isn't a huge amount. Secondly, FC + CC = TC, so one of your numbers is wrong. It is entirely possible that because you've only got .5 FC in your pool, you have a bloom of algae (or something) happening, which is consuming your chlorine. If it were my pool I'd shock it up to about 15 ppm, then let it drift down to around 5, then try to keep it there. I bet you'll find that your chlorine demand decreases.

I don't remember offhand where you are located, but if that doesn't decrease your chlorine useage, you might want to consider upping your CYA level a little bit...you have to maintain a higher chlorine level, but you can do it with less dosing if the CYA is higher.

They do make pucks of cal-hypo, although you cannot use them in a trichlor feeder. You can use them in a floater if it's not had trichlor in it before, but honestly the new pucks are garbage--they go to mush very quickly, and they add calcium instead of CYA.


Janet