Ben's DIY Graywater System

[bennelson]

The last two times the holding tank was pumped was May 5th and June 23rd, 2009.

That's 49 days between emptying the tank.

Also, I did NOT have the greywater system hooked up the whole time. Actually, looking at my calendar, it wasn't hooked up MOST of the time.

I had to go out of town for a few days, so I set the toilet back over to line water. Then, I didn't want to hook the greywater system back up (using the waterbed mattress) without a really good filtering system first, because there is really no way to clean out the inside of a waterbed mattress.

Yep, if I had the greywater system hooked up the whole time, I would have had WELL OVER 50 days between tank pumpings.

[bennelson]

I have still had a few concerns about filtering on my system.

Yes, a toilet is designed to have big things go down the drain, but the pump and the toilet water valve aren't.

The last load of laundry had some chunks of zucchini skin come out in the "lint sock". We have been using cloth napkins, and it turns out my wife was using one to squeeze the extra water out of shredded zucchini for a recipe. (Chocolate Zucchini Bread - it was great!!!)

Anyways, I would rather not have little bits of organic matter like that to go through my pump.

A while back, somebody mentioned "sand filters". I looked up some basic information and found out that they are used on swimming pools and are rather expensive. However, a home-made version is pretty straight-forward.

I grabbed a 5 gallon bucket and drilled a number of small holes in the bottom of it.



Then, I went down the street to the local landscaping supply. (The same place that I used their scale to weigh my Electric Geo Metro)

They carry rock, sand, etc, which I would need for my project.

As I walked in the door, the owner immediately recognized me and correctly guessed that I needed materials for some sort of "eco-project".

Yep! I explained my greywater system concept and that I needed supplies to build a sand filter - stones, medium gravel, small gravel, and sand.

He walked me to the back room, where he snipped off a piece of felt-like landscaping fabric. He then showed me where in the yard the cheap stone, pebbles, and sand were in the yard.

When I asked how much for materials, he said something like, "No charge, just let me know how it turns out. It's always interesting to hear about your projects."

I'm sure he read about my electric car speeding ticket....

I filled the 5-gallon bucket with a layer of big stones, small stones, big pebbles, small pebbles, and a top layer of sand.




I then stuck the flat piece of fabric as best I could into the cylindrical bucket.


I played around with the garden hose a bit, to see how fast water would drain from the bucket. I figure my washer probably drains roughly the same speed as the garden hose feeds. The bucket did seem to empty fast enough.

I brought the sand filter bucket inside.
Hmmm... Not sure of the best way mount the bucket in place. Oh well, it's still experimental anyways. I grabbed a chunk of scrap aluminum and set it over the top of my greywater storage drum. The 5-gallon bucket has a nice lip all the way around. That lip set on the edge of the storage drum and the aluminum cross bar. Good enough for now, but I will have to do something nicer later.



I ran my first load of laundry, and the filter seems to be working the way it should be.

I will let you know more if anything else happens.

[Daox]

Nice setup Ben. Any idea what the sand filter would have cost if you would have needed to pay for the materials?

[bennelson]

I think that bulk materials at the landscapers are $5 per 5-gallon bucket of materials.

5-gallon buckets can usually be bought a rummage sales for a dollar or two each. I have no idea what the landscaping fabric costs. I really only used a scrap.

All together this is less than $10 of material.

[bennelson]

My holding tank alarm went off yesterday.

It's a new record of just over nine and a half weeks since the last time the holding tank was emptied.

I think the first time it had to be emptied after we moved in was 5 weeks.

That means we have almost cut our water bill in half.


I haven't been using the sand filter. More than anything, it's a matter of space available in my laundry room. My laundry room is also the furnace, water heater, water softener, pressure tank, and pantry room.

It's just small and cramped in there. I do have a little bit of room to the SIDE of the graywater tank. It might be better for me to design some sort of filter system that goes there. Unfortunately, it could no longer be gravity-fed, so I would need another pump (which means money and electricity use!)

[Daox]

Wow, thats quite the improvement.

[Binger]

when I was cleaning carpets we had a system in the vaccum that had a square metal mesh basket. This let dirt go though, some hair still got through...but it caught just about everything...I'd add one of those to your sand bucket filter to catch the big parts going in to that.

[bennelson]

Had the holding tank emptied today.
That's 55 days since the last time.

[wyatt]

Someone correct me if I am wrong, but I think your sand filter is set up backwards. You want to filter out the large stuff first (with the large rocks), and filter out smaller and smaller things as you go down. I would even guess having the layers separated would be even better for easy removal of junk. The way you have it set up it looks like the best filtering is done right away, meaning all the rocks at the bottom have very little use.

[bennelson]

It is set up so that the big rocks can't go thru the hose at the bottom, but sand would if it was on the bottom.

The rocks don't filter anything, they just hold up the other materials, and allow a path for the water to go thru. I need to rework my filter, as it was sort of thrown together in the first place. I want to design something that works a little better in the space I have.