Hey Guys -
Long time no post (I mean REAL long time).
Got a pool question - of sorts. Given the high cost of electricity here in
the northeast, I was thinking or running my pool filter motor at night to
get the off-peak rates. So, my question - Is my family going to swim in
emerald green water all summer as a result? Has anyone thought of doing
Any help/opinions would be appreciated.
(put a dot in between my first and last name)
Green grows when chlorine and other chemicals levels drop below a certain
amount. The only possible thing I see wrong is that during the daytime,
pollen and dirt will settle in the pool and go to the bottom without the
pump running and unless you have a creepy crawler cleaning your pool at
night thats where it will stay until you cleen or sweep the bottom.
My Name says...
> Got a pool question - of sorts. Given the high cost of
> electricity here in the northeast, I was thinking or
> running my pool filter motor at night to get the
> off-peak rates. So, my question - Is my family going to
> swim in emerald green water all summer as a result? Has
> anyone thought of doing this?
It has always been my understanding that the pump should be
on during periods when the pool is in direct sunlight.
That's because that's when algae grow best, and because
chlorine is dissipated by ultraviot light, and you need to
keep the chlorinated water mixing. Otherwise, water at the
surface will become chlorine depleted and algae will bloom
there. If your pool uses a chlorinator that only works when
the pump is on, it would be particularly important to run
the pump during sunlight periods.
Anyway, that's what I do most of the time - match the pump
to the direct sunlight period. And when thunderstorms are
expected. I guess that doesn't match your lowest pricing
time, but if you have some shade, maybe the sunlight period
is short enough to make up for the higher cost per KWH.
At one time I contemplated a switch that would sense bright
sunlight and turn on the pump accordingly. That still might
actually be a good way to do it it you could find such a
switch and didn't mind doing a bit of rewiring.
Let us know what you end up doing, and how it works out for
If green water is an issue it is algae that you need to control. I've
had pools for years and have watched in amazement as my neighbors became
slaves to their pools. Chlorination, at modest levels is one way of
controlling bacteria, etc., but, it is not the most effective way of
dealing with algae. Chlorination is not nice if your users relieve
their bladders in the pool as it then yields chloramines which irritate
Algae requires phosphorous to grow. Phosphorous gets in to your pool in
a myriad of ways, including dust and dirt that is blown in with the
wind. A small amount of lanthanum carbonate, mixed to form a slurry and
the poured into the pool or skimmer is a good way to eliminate algae.
The lanthanum binds the phosphorus so that it is no longer available for
the algae to use it. I don't believe Lanthanum is toxic, nor is it
Leslie's used to sell lanthanum carbonate. The last time I was there
you had to buy a lot of other "stuff" with it that ran the price up for
no good purpose.
5 year old pool in Phoenix AZ. Pool builder's startup guy set the
timers to run at night, left them that way ever since. Never a green
pool. Well, other than the fact that the Pebble Tec finish is green.
Speaking of electric rates, the local utility, Salt River Project,
just sent around a letter announcing their new rate plan. Used to be,
they had 2 rate periods - Winter (NOV-APR) and Summer (MAY-OCT).
Summer air conditioning season, of course was higher. They have now
added a third rate period, Peak Summer (JUL-AUG). That's when the
temperatures here hit 110 or more. I can hardly wait to see what my
Peak Summer electric bill looks like.
I used to follow the "run during daylight" doctrine.
Then I thought, why not let the stuff grow in the daylight, and give it
a whallop of filtering and chlorination at night, when the chlorine
isn't dissipated by sunlight. In theory it should sterilize the pool of
both microbes and algae during each night, and algae can't really get
going too much from zero in one day. And nighttime chlorination is so
much more effective, more sanitizing power per dollar, than during the
Now this won't do for a public pool where you have to keep the water
sterile during daylight usage. You gotta have chlorine and filtering
then to take care of all the "cheek wash".
But it certainly works well, and economically, for my residential pool,
to run only about 6 hours from dusk. On occasions when there is
daylight bathing load, we turn it on manually.
(This is a pool with a chlorine generator.)
Richard J Kinch says...
> My Name writes:
>> So, my question - Is my family going to swim in emerald
>> green water all summer as a result? Has anyone thought
>> of doing this?
> I used to follow the "run during daylight" doctrine.
> Then I thought, why not let the stuff grow in the
> daylight, and give it a whallop of filtering and
> chlorination at night, when the chlorine isn't
> dissipated by sunlight. In theory it should sterilize
> the pool of both microbes and algae during each night,
> and algae can't really get going too much from zero in
> one day. And nighttime chlorination is so much more
> effective, more sanitizing power per dollar, than during
> the day.
Well, it's more effective if you're still not using
stabilizer. Would this still work if you were using
stabilized chlorine at night?
And, I'd also like to second the idea of whoever suggested
controlling phosphates as a way to control algae. In my
experience this works quite well. The product my pool store
carries is PhosFree. Superchlorinating can remove nitrogen
compounds, but apparently doesn't burn off phosphates at
I'd like to thank you all for the great information you gave on this
subject. I have had a pool for 20 years and never heard of the phosphate
thing before - I'll have a pointed discussion with my pool store about that
one. I'll follow up with the group in a couple months, the cover won't
come off until memorial day week end.
My Name says...
> I'd like to thank you all for the great information you
> gave on this subject. I have had a pool for 20 years
> and never heard of the phosphate thing before - I'll
> have a pointed discussion with my pool store about that
> one. I'll follow up with the group in a couple months,
> the cover won't come off until memorial day week end.
The phosphate thing was never a problem here until the
mid-1990's. Well, except for people whose lawn service
broadcasts a regular supply of fertilizer into the pool.
But gradually everybody started having algae problems.
Over time, the cause became clear - the phosphates were
now in the water supply. Not enough to affect potability,
but enough to significantly raise the levels in pools.
Algae absolutely needs phosphates to grow, but it only needs
a tiny amount.
And the source of the phosphates - chicken shit. Seriously.
A large number of poultry processing operations moved into
the watershed, and the "waste" was converted to fertilizer
that began to be widely used by area farmers. It's high in
phosphates, and just runs off the fields into the creeks and
rivers, and eventually into the lakes we draw water from.
So now pretty much everybody uses PhosFree, or some
equivalent, based on the free testing the pool stores
provide, and it really works well. But in your area, it
might not be a problem, depending on the tap water
situation. On the other hand, it doesn't take much lawn
fertilier to get you in trouble if it contains phosphorus.
Superchlorinating will neutralize the ammonia, but not the
phosphates. Anyway, testing your pool water will tell the
No filter I'm aware of removes or prevents algae, that's chemistry.
Filter use is somewhat dependent on how much the pool is used (and
what oils, etc. they might have on their bodies) and what else and
how much of what else ends up in the water.
Our pool is mostly used by the freakin dog, and consequently SWMBO
insists the filter run 24/7 during the season. It's worth to me
whatever it costs to hold that noise to a minimum.
There's oodles of "expert" advice available on the web, but I see no
problem with your idea for a pool that sees "normal" use.
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