Unless you are a very smart engineer or a scientist, you can't.
The MSD2578VEW is a Maytag side by side that has a built in water filter.
You could use the following link http://www.wikihow.com/Make-Your-Own-Underwater-Aquarium-Filter. Or maybe adapt another smaller tank to be a Bio filter using the same principles.
Simply buy some filter fiber from a Pet shop, then open your filter and only replace about half of the fiber that is in there so that the filter keeps at least some of the bacteria that are doing the job of removing the poisons from your water.
This filter can be used on aquariums up to 20 gallons.
You can buy a livestock water tank and a filter and that works fine.
Pool water needs to be regularly sanitized with some sort of system that kills bacteria and other pathogens. Then the water needs to be run through a filter to remove dust and bio materials to keep the water clear
The plant has a dome like structure built with bricks. A slurry of cow-dung and water is made in the mixing tank from where it is fed into the digester.
When it stops cleaning the water properly. short of checking the water with a microscope for suspended particles if the filter is not filtering properly your pool wil suddenly require more chlorine more often because more of it will be taken up dealing with an increased bio-load in the water.
I personally prefer the biowheel. The important thing to remember is that you must always keep it running and never loose your aerobic bacteria in the filter medium. Always rinse the media in clean water that has no chlorine and never clean all the media at the same time.
You can use water filter straw or water filter bottle to filter water which is quickly purify water and the water is safe and fresh to drink.
There are many books and articles on the internet about this VERY complicated subject. -First step is to get a sample of the water analysed to determine which filters you need.
Biological, because the speed bio build always goes first and can do more damage than any other build if done right. There're a lot of guides for speed bio on the web.