Experiments in small batch water filtration/recycling

Now that I have the kitchen cabinets done (except for the doors ;-) I can get back to the plumbing design, because I know what size/shape space I have to fit it into. That takes me back to the water recycling experiments I started a few YEARS ago, when I built these DIY sand filter buckets to play around with. Originally I was following the work of this guy and his sand filter designs, despite his buckets being about 10x larger than mine.. When I built the buckets the first time I made baffles to go inside, but quickly abandoned because they were so small they got clogged. So, I have done away with the baffles and just used a kitchen sieve like one would use for sifting dry ingredients together to keep the sand in place. My goal is to be able to wash my dishes and get the water clear/clean enough to dump into the tank under the floor. From there it gets pumped through an activated charcoal and a biological filter back up to the faucet to be reused. So, this sand filter step is pretty important.

After eating a whole bunch of good food I have made a mess. So, let's go outside and wash some dishes, see how much water I use to get the job done on a daily basis, and then what I have to do to treat X volume of water. So far I seem to use 3 batches of water: one to pre-rinse, one to wash and one to finish rinse.

This is the pre-rinse water. The total volume I use on average is about 8 gallons of water total.

 Packed into the bucket is about 20lbs of pool filter sand, and added to it is about a palm full of alum, a mineral salt often used in pickling, but also municipal water filtration. Alum changes the ionic composition in the water and attracts particles to it, which sink to the bottom if allowed to sit.

In the bucket goes my swill.

 After sitting overnight I opened the spigot at the bottom of my experiment bucket, and out come clear, clean, soap free water! I would feel comfortable drinking it after running it through the charcoal and bio filter.  For now I feel comfortable using it as the pre-rinse and soap/wash steps of my dish washing routine. Now all I need to do is find a bigger bucket that can hold the total volume of water used at a time. I suppose I will also be wise to buy a couple of enamel pans to go on the sink that I can use while actually washing dishes to help keep track of the volume of water as I go along. The tank under the floor can hold 15 gallons, so I could have 3 total loads worth of water in the system at any given time: 1 in the filter under the sink and 2 in the tank under the floor. Weight is of course an issue, with each gallon of water weighing 8lbs x 24 gallons + 50lbs of pool sand that's 250lbs! I will have to make sure that when I travel I empty the tank and dump out the filter. I want to implement the same design in principal in the bathroom/clothes washing water recycling system, but the space is much more crowded back there, so I'll have to figure that out. Projects! Never boring!