This isn't universally applicable, but it gives you an idea of how
it's done. This is a water filter that uses diatomaceous earth as
the filter medium. Every few months, it needs to be cleaned out,
and the medium must be replaced. Generally, you can go longer
during the cold months without cleaning it out, and must clean it out
more frequently in the warm months, when there's algae growing.
By the way, I'm not a professional. If you are still feeling trepidation after reading this article, do yourself a favor and hire a pool cleaning person.
Here's a picture of the whole system. The timer switch box is
open.
Flip the switch to turn the pump off, if it's not already off.
If the timer's about to turn the pump on, loosen the nuts that flip the
switch. You don't want the system turning on while you're working
on it.
This is the strainer or pre-filter. This is used to catch
debris before it
goes into the filtration system. This strainer should be cleaned
out every few days if possible, and a minimum of once a week.
Inside there, it's a plastic strainer. Take it out, and rinse
the crap out of it.
Walk over to the skimmer, and look inside. It's another
strainer, with all the leaves the skimmer caught.
Clean it out. There are still some leaves in there. I
didn't do a good job, but it's good enough for now.
Returning to the filter... there's a wrench. I bought a wrench
strictly for this purpose, and keep it on there. More than once,
I forgot to bring my wrench, and that meant work was delayed another
week -- and that sucks because you have to schedule at least an hour to
clean the filter, and that hour is gone. Unscrew the nut,
and take off the band that holds the canister together.
The nut's off. The collar, spring and a washer also come off.
Keep them together, and nearby.
The band is removed. At this point, there's still water in the
filter, so, don't remove the top. In fact, you should probably
drain the filter first, but, I rarely do.
Give a twist to the air relief valve, located on top of the
canister. This allows air into the canister. The water will
start to drain out of the filter,
backwards. This can result in water draining into the pump and
into the pool. Do I care? Not really. But
professionals are fastidious, and will drain the water through the
appropriate outlet pipe.
Note that I am not backwashing
anything, so only a small amount of crud will come out. Much of
it is left on the filter grids or in the leftover water in the
container. The way I see it, the stuff will just get swirled up
and caught on the filters once everything is cleaned. I'm not
being perfectionist this time.
However, at least once a year,
I have to do a thorough cleaning of everything, meaning backwashing the
canister to get rid of all the murky water. (In addition to
washing everything.) It also requires soaking the filter grids
for a while in filter grid cleaner.
This valve rearranges the plumbing so that you can drain water out
of the filter. I have it dribbling some water out, but, you can
be really "pro" and get a hose attachment and drain out the entire
filter onto the lawn or into a real drain. The water exiting is
murky because the filter medium is coming out.
One the water's drained from the filter, remove the top.
Here's what it looks like inside. Note that there's a huge O-ring
that's a gasket between the top and bottom. Make sure it's clean,
and
there are no rocks on it. You can clean it off and lube it with
silicone grease.
If you look at the top, there are two handles that read "LIFT
HERE". Lift with those handles, and pull the filter out of it's
canister.
I don't have pictures of me carrying the heavy, dirty filter to this
dirt patch. The thing is heavy, and you have to be real careful
not to drop it or even hold it close to your body, because you will
damage the petals of the filter.
Here's a picture of the filter being hosed down. The water
knocks the dirty filter medium off the petals, revealing that they're
made of white fabric.
On top of the filter are a couple of wingnuts. See the picture
above. Loosen them and remove the white top part of the
frame. It reveals a flimsy black guide that kind of holds the
filter petals upright. Remove that too. The petals lift
out. You can then hose them down more completely.
Here's a single petal, and there's still gunk on it. Hose it off.
After all the petals were removed and washed, you start to
reassemble the filter array. There's a guide along the bottom to
help. All the petals are identical, except for one. That
one is shorter than the rest. You can see the short one in the
photo below - note that the end doesn't extend as far around as the
others.
The short petal allows the vertical outlet tube to attach to the
array. That's shown in a picture later.
Here's the entire array, put back together. Note the short filter
on the left.
The plastic holder thing fits into place. This helps to hold the tubes in the right position, so you can put the white thing on top. Imagine if you didn't have this black thingie - you'd have to align all those pipes by hand.
I don't know what this white thing is called, but, it goes on
top. You have to put the wingnuts back on. This thing is full of
tubes, and filtered water flows up into the white thing. The
water's all combined and it then runs down the outlet, which is to the
left in the photo below. It's not that thing sticking up - it's
that curvy tail.
This photo should have been rotated. The outlet tube is at the
top of the photo. Note the short petal that allows the tube some
clearance.
Carry the filter back to it's canister. You install it by
sticking the tube that's sticking up into the outlet tube. You
can see the outlet tube to the right - the vertical white tube.
Replace the top.
Reattach the band. This is a pretty difficult task, because it'll
keep falling off. Just press it into place, and try to get the
bold into the hole. Have the nut and spring assembly nearby so
you can just pick it up and install it.
Then screw it on tight. This particular assembly has a spring, and when the coils of the spring touch, there's enough tension. You don't want to over-tighten and damage something.
Open the top valve, and then turn the pump on. Water will
start filling up the canister. Note, never run the pump
dry. You need to make sure the water's being sucked up into the
pump. The water is used to cool the pump, and if it's run dry,
it'll overheat and break.
Once the water filles the canister, it'll flow out the top.
Close the valve when this happens.
In the following video, I made a mistake and turned on the pump
without opening the valve on top. Air flowed through the filter
and out into the pool. Ooops. I had to open up the top
valve to let out the water. You do this so water fills the
canister all the way to the top.
There's more stuff to read here, at my blog/book thing.