how often to SHOCK ?

[dolphin]

I have shocked my outdoor pool and it took 4 days to get it from algae green to crystal clear.
the methods were recommended by TFP ( meeting the 3 criterias etc..)

What i know...
1) using the pool calculator.
2) CL, pH, TA, CH, MA, CYA Langelier index.
3) Stabilized Chlor: Triclor 95%, Diclor 65%,
4) Non-stabilized chlor: Cal Hypo 65%, Sodium Hypo 13%.
5) Shocking the pool when:
-water becomes cloudy, DPD test kits shows up pink in the test kit, a loss of CL overnight.
What i am not sure of:
I have an outdoor pool at the 22 latitude (tropics). 7500 gallons w/sand filter.
When i shock the pool, (using the 'meet the 3 criteria' ), the water becomes really crystal clear and remains that way for weeks at 2 ppm or 3 (depending how much CYA is in the water).
the question is, i notice alot of dust and fine particles blowing into the water, obviously the sand filter cant catch
the finer stuff but eventually it ends up in the filter.
The real question is this :
at 2 ppm or 3, can the Chlorine really disolve or vaporize the stuff that does get stuck in the filter or wherever it is suspended in the water or on the floor ( i do sweep to keep the algea from getting comfortable or settling in)
is it normal to shock every 2 weeks if the water suddenly starts to slowly become cloudier?
( i do monitor the CYA, CL , pH etc , etc very often so that it doesnt wobble out of control )

 

[dolphin]

just to add to the last question i posted :
with all that stuff blowing into the pool - whether it remains in the filter or water, CAN or IS the chlorine strong enough or can it keep up oxidizing all that stuff mentioned?
or do i shock as part of a routine to eliminate all this foreign matter blowing in.
i do try to sweep and keep leaves out and keep the skimmers , strainers virtually debris free - anything to help the chlorine do its job oxidizing the stuff out.
is this the usual war i have fighting the outdoors from making a home in the pool?

 

[dolphin]

finally:
i was hoping, once the pool is chocked and the water is crystal clear ( as was the case ).
regular vac, cleaning the screens etc, etc . no one really using the pool, the water would INDEFINITELY stay clear.
but i'm discovering that is not the case
im wondering if shocking on a regular basis is normal or not even if the pool is used very little

 

[dolphin]

Re: How often should a person shock their pool?

what happens to all that stuff that gets blown into the pool ( dust, dirt mainly. I can literally see it get blown into the surface).
its almost mathematical in a way - at 1.5 or 2 ppm is it possible for the chlorine to really get rid of or oxidize all that stuff (keep up) with it all??

 

[jblizzle]

Post up your test results. Specifically what is the CYA? Your FC sounds way too low.

 

[dolphin]

CYA 7 ppm, ( i have a tarps covering 80% but not touching the pool water), I'm in shock mode at the moment but the FC where between 2 and 3 ppm. but if did have the covers off when the guest had to use the pool.
i'm kinda leaving over to the side of your thinking, the FC levels too low.
if if have the covers off and the sun 'literally is at 80 degrees overhead for 3 hours on end (which it does). it might be possible that the FC dives from 3 to who knows???
But after the sun sets or no longer hits the pool, the fc is near 1.5 or 2.5 but maybe its still not enough for an outdoor pool??

 

[jblizzle]

How did you measure 7ppm? The test starts at 20-30ppm.

 

[dolphin]

i'm guestimating its at 7. with the rod sitting at the bottom ( that would be the 0 mark), i can still see the black dot ( 80% of it blocked out but i can still see the black black dot ). i'm guessing its around 7

 

[dolphin]

but you might be right... with the tarps off , the blast of sun ... the guest jumping in with sweat ( it does get very very hot and humid down here)... and my being to shy to vacuum the pool and clean the strainers, too low a CYA, too low FC - all might be just enough to for the chlorine to not keep up with the demands maybe ???

 

[dolphin]

i know CYA protects the CL but i just dont want it so high that im stuck having to have a higher levels of daily FC's or higher shocking levels because the CYA is too high...
I use the Pool Calculator to monitor the levels - which in turn usually does do a really good job.
i got away with really clear low chlorine demand for 2 1/2 months! in a 85 degree almost directly above sun (except now i use tarps to block the sun when not in use). the exception is when the tarps came off and the guest im thinking washing her sweat off in the water i think set it all off.
as you said a dangerously too low a FC might of triggered the cloudiness dirty water higher than normal chlorine demand situation

 

[jblizzle]

With hardly any CYA, the FC will be gone quickly in the sun. I would raise it up to 40-50ppm and increase the FC accordingly.

It seems like you need to follow the SLAM process completion again. And then maintain adequate FC.

You should not have to "shock" as you say on a schedule.

What are you using to add chlorine?

 

[dolphin]

i use Triclor bits slowly desolving in the pool and i boost using Sodium Hypo (kept in the fridge so as to not degrade). The liquid is of good quality clear and yellow in color. i might of slipped not keeping the FC's above 2 or 3 for a couple of days or more not vacuuiming cleaning the screens regularly and boosting the chlorine as soon as the sun stops casting over the pool (around 5 pm).
but it might of been enough for the organisms to get a foothold.
I'm hoping by using Trichlor the CYA will creep up and acidy the water while i boost the CL levels which de-acidify's the water.
all the while watching the TA levels

 

[dolphin]

what i did is i got a small tupperware container, drilled a few small holes in it. the container is just big enough to fit 1/4 of of 3" Triclor tab in the skimmer. it takes about 2 weeks to fully disolve a 1/4 3" puck

 

[dolphin]

i'd like to know what the SLAM process involves too if it helps any

 

[dolphin]

one pool guy i get my supplies from at times say the pools down here are kept at 100 ppm CYA ! Woa! thats crazy too high.
i'm just worried i blow thru the 50 - 80 mark by using the Triclor or not being able to shock whithout having to use a really high level of chlorine to do so

 

[dolphin]

yah the SLAM process is what i already know : given what the CYA level is + the TFT FAS kit i have + pH lower (7.1 ~ 7.2) to accomodate the high pH of Cal hypo , i usually do quite well shocking the pool.
I managed to get the pool out of a literally swampy green pool to crystal clear in just 4 or 5 days! a record lol.
i think the water became cloudy again ( in 2.5 months of clear water) from trying to increase the TA and having the tarps off and having too low an FC it might of been enough ( like a match too close to a flame) for the organics to just be able to take over.
when i recover / come out of shock , i'll maintain a higher CYA and a much higher FC level

 

[Richard320]

Re: How often should a person shock their pool?

To 'shock" - the term here is SLAM - you should shock it when it needs it.

For me, that means.....never.

Chlorination, however, is a daily thing, at least during the season. As the water cools and the sunlight decreases, I can skip a day or two here and there with no problem. A pool is like a pet (psst, look down)

 

[zea3]

Re: How often should a person shock their pool?

The filter captures the dirt and debris until you rise them out. The chlorine oxidizes the algae and other microscopic organisms, and the by-products of the oxidation are caught in the filter. The chlorine will oxidize the bacteria that are clinging to the dirt when it blows into the pool, but it will not oxidize the dirt itself.

 

[linen]

Re: How often should a person shock their pool?

what happens to all that stuff that gets blown into the pool ( dust, dirt mainly. I can literally see it get blown into the surface).
its almost mathematical in a way - at 1.5 or 2 ppm is it possible for the chlorine to really get rid of or oxidize all that stuff (keep up) with it all??

Unless your cya is also too low, you should never let your FC get that low.

I also do not need to shock (SLAM) my pool regularly. This year I went to SLAM level when I opened (I probably didn't need too) and I also went to SLAM level when I closed.

 

[dolphin]

Re: How often should a person shock their pool?

hmmm.. ill have to increase the FC 'above' what is considered 'ideal' (taken that the CYA is 0, ideal meaning 1.5 to 2 ppm).
since the sun shines pretty strong with dust blowing about, it might be wise to start on the 'high' side of FC's to see how well the chlorine handles the organics ( of course, using the pool calculator to factor in CYA).
i think the industry error is :
when you look at the test kit and it says 1.5 to 2 ppm is ' IDEAL' well thats great for an idoor pool with no sun, no dirt laden wind. Its almost like saying: if your pool is outdoors then its 'rough 4x4 country' itll take a rugged chlorine approach.
when i finish the SLAM (shock) i'll keep the levels to 3 or 4 FC ( higher if the CYA dictates its. Or better yet, on the high side of what the pool calculator depicts to be for CYA levels)