i have had a few cheap backyard frame pools, and pretty much the "filtration systems" they come with are only good for people that never get in there pool dirty, have no friends, no kids, no dogs, nothing but time to wash or replace the filter constantly, always keep the pool covered, you get the idea.

my pool is a 16' round 42" deep.  think it holds about 4000 gallons. basicly between all the people, and our 2 filthy dogs, the little cartridge filter was not cutting it.  it hangs in there for the 1st couple weeks then the water just gets too nasty. even though i come home and sray it off every day and change it once and a while.  the filtration setup that comes on the pool should probly only come on somthing with a few hundred gallons. whatever, i think it sucks. in the picture obviously im also dealing with some algae.

Step 1: The Basics

why do you want a sand filter? because sand is actually a really good filter, thats why most larger pools and aquatic facilitys and even your nicer backyard above ground pools use them. 

how do they work?  well its actually really simple. a "normal" sand filter is a sealed container half full of sand, water is forced though the sand by the pump. ya its that simple. 

how exactly?  a pump forces the water into the top of the container, usually through somthing that spreads it even so its not just a jet of water blasting a tunnel in the sand, you want a nice even sand bed the water has to go through. in the bottom there is somthing that usually looks like a a bunch of little pipes with slits in them the sand cant fit through that connect to a big pipe, that is the outlet where clean water comes out.
<p>So on the pump thing, I've seen a lot of people on craigslist or at flea markets and stuff that have hot tub pumps, in working shape, for like, super cheap. Might be a good source for a pump that will move a little bit more water if you get the right one.</p>
I'd love to see someone make one out of a five gallon bucket and some pipe. Maybe you could put it directly under the skimmer and pipe it directly into the lid? A couple ball valves and some tees for back washing?
<p>The big problem with doing a 5 gallon bucket is just going to be the surface area of sand that you have available to filter. There are some calculations that we do on commercial pools that tell you how much sand you really need- you might even be able to do something where you run multiple buckets, but it's pretty important to make sure that you have enough surface area to filter the amount of water you are dealing with.</p>
<p>how powerful IS the filter you used? (so anyone doing this project can avoid that pitfall by buying a stronger one)</p>
<p>I know this is an old instructable, and you've probably refined the filter a bit by now, but do you even need an &quot;in&quot; pump? if you have a direct connection to the pool, with no possible airlocks, the level of the water in the filter should stay the same as in the pool, the water just flowing naturally into it. I'm planing on making a filter for grey water before it goes onto the garden (just to reduce any smells), and I was thinking &quot;gravity sand filter&quot; and found this... mine will probably need gravel to avoid the &quot;blast through the sand&quot; effect</p>
my neighbor had a big 1 horse pool pump..........................I got it for......................$5 WHEN HE TOLD ME THAT I WENT RUNNING FOR MY MONEY BEFORE HE COULD CHANGE HIS MIND
I like your ingenuity. This a great solution, for your pool and it also has real application to fish pond builders as well. Sand filters reallly do an excellent job. The use of the overflow pipe is clever; the pump is really underpowered. A suggestion is to make use of some hydrochloric acid to buffer your pool and keep the algae down. This will reduce the chlorine required. Check the pH frequently. Even with two dogs, your approach will pay off with crystal clear water.
Bleach can be used too, as long as it's a chlorine base, just dont pour it in raw, (same with the acid by the way) or it will sink and decolour the liner if you don't dilute it first!!
you can put bleach in the pool with out diluting it first i i do it all the time and its more effective <br> <br>wont hurt any thing really the water in the pool dilutes it any ways
Using hydrochloric acid has several benefits - just think of it as ultra fast acting chlorine (HCl = Hydrogen + Chlorine!) : It gets the pH down fast as it is an acid, it's the fastest acting chlorine you can find (great when you have to superchlorinate an algae infested pool) and it's a darn sight cheaper than using buckets of chlorine tablets! <br> <br>I cannot remember what our equivalent doses my stepdad used though (20 odd years ago!), but Google will help you find it for you!
yes those tablets are expensive. the bucket pictured in the backround was powdered chlorine shock i got for free at work because some one ordered lithium shock and i dont like using that in the pools at my building. i normally just buy liquid pool shock and throw some stabilizer in
bah, remove the chlorine and put in some fish, they'll eat the algae and any insects that land in the water.
Do you have a deformed dog in that Picture?
motion blur / crappy phone camera
If you have outdoor dogs that like rubbing themselves over the grass, then you will get a green pool :) I've seen the colour of the water when my mom managed to catch and shower her mutt ;) <br> <br>If you were using a cartridge filter, whatever the size of the pool, you will end up with a green pool unless you declare chemical warfare on it - the pores on the filter are still to big to filter out the smallest algae, and even after superchlorinating the water, and everything is dead, the filter just cannot take the crud out of the water! <br> <br>My parents ended up getting a 6000 gallon-ish pool complete with a sand filter, though the pumps have a tendancy to die after a few years - and given the price of a pump and filter system, compared to yours, this could be a great replacement idea. <br> <br>A question; do you have a method on hand to flush the filter? - push a couple of dozen gallons of water the &quot;wrong way&quot; through the sand, and dump the outflow (don't pump it back into the pool whatever you do!), so it resettles the sand - and the backflow will flush a load of crud out from the sand and refresh the filter!
yes i do &quot;backwash&quot; the filter, i take the pump on the clean side of the filter, flip it around, disconnect the plumbing on the dirty/water in side and let it hang so it pumps water through the filter in reverse. it usually looks NASTY. then i put it back and let the water flow through the normal way a few minutes until the sand settles then hook it back up
Great and useful work, thanks for sharing.
thanks for the compliment and your right, im actually a certified pool operator, i just dont care, i dont want to spend alot of time balancing my crappy backyard pool when i do it all day at work. i just want the water to look clean

About This Instructable




More by 7808:$20 off the floor fold up wall-hanging dog bed (65lb dog) cheap fast DIY deck or patio awning canopy diy non- pressurized sand filter for backyard pools 
Add instructable to: