Time of day to add bleach for proper FC maintenance...

Feb 28, 2009
49
College Station, Texas USA
Pool Size
9000
Surface
Plaster
Chlorine
Liquid Chlorine
I live near Houston, so it's getting warm and sunny down here.

I have a 3 gpd Stenner pump with an electronic timer. I use liquid 8.25% bleach. I am having some difficulty maintaining a FC level that I consider acceptable. Water stays clear, but mustard algae (??) starts to form on the shady part of the pool.

My chemistry:
FC= 1.5ppm (I know this is low)
CH= 200
CYA= 50
PH= 7.6
TA= 90

I've just added enough CYA to boost the CYA to 70, and bumped the calcium to get to closer to 300.

The big issue is maintaining a high enough FC level. My question is about the injection times for the bleach. Currently, I do three 40-min intervals a day (about 10 oz of 8.25% bleach), at 8:00 am, 12:00 pm and 8:00 pm. I've just added two more of the same intervals at 1:00 am and 3:00 pm. So, beginning today, that is a total of 50 oz per day. As I was adding the new injection periods, I wondered about whether there is a strategy for WHEN to put in the bleach. Am I better off doing it all over night, and not in the middle of the day, or spreading it out like I do now, throughout the day and nite. The day-time injections may be sub-optimal, as it's the sunniest part of the day.

So, what say you all?
 
at 50 oz your adding 3.7 FC a day now and that is about right, I think because you have gone below 4 FC you have some algae taking hold, every time you go below that level things can grow.. the answer is more FC..

go ahead and start a SLAM at your current CYA level, pass the OCLT, then take your CYA to 70 (basically a SWG pool level) and then always keep FC above 4, even if you have to use 60 oz or 70 oz per day, the goal is to keep fc above a certain level not use the least amount of bleach :)
 
Thread Status
Hello , This thread has been inactive for over 60 days. New postings here are unlikely to be seen or responded to by other members. For better visibility, consider Starting A New Thread.