Hi, to shock, would you guys suggest cal hypo granular or bleach from sams club? 35,000 gal cloudy and fc was at absent. hey thanks!
cal hypo vs bleach?...
- Thread starter marty
- Start date
Hi marty, 
Bleach would be my first answer, but could change from that if you posted a full set of test results.
Follow these instructions here:
what-we-need-to-know-to-answer-your-questions-t10341.html
Chuck
Bleach would be my first answer, but could change from that if you posted a full set of test results.
Follow these instructions here:
what-we-need-to-know-to-answer-your-questions-t10341.html
Chuck
Oh, once you do that RobbieH here has a HUGE pool too, I think close to 44,000 gals! 
Got any pic's?
Got any pic's?
That was fast, in ground, pent air clean & clear cartridge, plaster. i will have cya at 30ppm
how many gallons should i buy? (btw i saw onlike for 35,000 you would add only 3 1/2 pounds of cal hypo, is this cheaper then bleach?)
how many gallons should i buy? (btw i saw onlike for 35,000 you would add only 3 1/2 pounds of cal hypo, is this cheaper then bleach?)
You can calculate how much bleach it will take for you raise your pool FC to shock level by using the the Pool Calculator (link in my sig line). We can't really tell you exactly how much bleach you will need in total because it all depends on how dirty your pool is and how disciplined you are at shocking.
I would not reccommend cal hypo to you because you are on a cartridge system and you run the risk of raising your CH too high with the cal hypo.
I would not reccommend cal hypo to you because you are on a cartridge system and you run the risk of raising your CH too high with the cal hypo.
The answer depends on your CH level.
If you are at the low end of the recommended range of 250-350, then use the cal-hypo. It is way easier to get the required FC into the pool. I find that it does float and when sucked into the skimmer socks does seem to degrade them a bit faster, so if you have socks on, you might take them off.
Now, how you KNOW your CH is important. Your own testing is best. Test strips are useless and pool store testing is always suspect; believe them only if they are consistent and reflect the changes you know have occurred in your pool.
Otherwise, given your volume Liquid Shock from a pool store would be second choice. You may find 10% or 12% locally. Or bleach, 3 packs from Sam's or grocery store house brand. Gonna take a lot of bottles to get you to shock level, stock up as it may take a few days to burn out anything that has started growing.
You will need to do a full, proper shock, not just hit the shock FC once and then done.
If you are at the low end of the recommended range of 250-350, then use the cal-hypo. It is way easier to get the required FC into the pool. I find that it does float and when sucked into the skimmer socks does seem to degrade them a bit faster, so if you have socks on, you might take them off.
Now, how you KNOW your CH is important. Your own testing is best. Test strips are useless and pool store testing is always suspect; believe them only if they are consistent and reflect the changes you know have occurred in your pool.
Otherwise, given your volume Liquid Shock from a pool store would be second choice. You may find 10% or 12% locally. Or bleach, 3 packs from Sam's or grocery store house brand. Gonna take a lot of bottles to get you to shock level, stock up as it may take a few days to burn out anything that has started growing.
You will need to do a full, proper shock, not just hit the shock FC once and then done.
With careful shopping bleach and cal-hypo tend to cost about the same, with cal-hypo tending to come out slightly less when there is a major sale, and bleach slightly less the rest of the time (bleach prices are more stable). The big question is if you want or can accept the added CH that comes along with cal-hypo. If CH is already high using cal-hypo is a bad ideal. If CH is currently too low, using cal-hypo can be a very good deal.
There is no way to calculate how much total chlorine you will need, just the amount you need to add right now. Depending on what happens you might need to add more very soon, or not for a while. To get to shock level with CYA at 30, you need about 7.5 gallons of bleach, or 6 lbs of cal-hypo (65%). However, you haven't given us enough information to tell if you need to shock or not, and if you do need to shock it is unlikely that a single application of chlorine will be sufficient. By the by the Pool Calculator is a great way to figure out things like this.
There is no way to calculate how much total chlorine you will need, just the amount you need to add right now. Depending on what happens you might need to add more very soon, or not for a while. To get to shock level with CYA at 30, you need about 7.5 gallons of bleach, or 6 lbs of cal-hypo (65%). However, you haven't given us enough information to tell if you need to shock or not, and if you do need to shock it is unlikely that a single application of chlorine will be sufficient. By the by the Pool Calculator is a great way to figure out things like this.
A basic rule of thumb, at least in the UK is Calcium Hypochlorite is best for soft water areas, whereas Sodium Hypochlorite (bleach) is best for hard water areas. I live in a soft water area and cal hypo isbetter as it keeps up CH levels, whereas in the south of England bleach is used more in small pools or chlorine gas in large pools
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