Rain Water Purification Thought

We are buying some land and I plan to build an Earthbag/Cob home. My intent will be to slope the roofing system to one central collection point and collect the rain.
I will have a 5 gallon bucket covered by screen and a paint strainer in the bucket as a first line of cleaning. The plan then is to collect it in a 1500 gallon cystern where it will be emptied into a 55 gallon drum full of sand, wjich will empty into another with activated charcoal, which will empty into another with a 12v medical grade uv bulb in a sealed quartz crystal jar epoxied into the top.
Will this work?

Howdy Richard, sounds like a sand filter?

http://oasisdesign.net/water/treatment/slowsandfilter.htm

Here is a permies thread with more info too.

https://permies.com/t/25198/toxin-ectomy/Water-Filter-Systems-water-testing

Richard Walker : Regarding the uv light, a local 'cider mill' uses it exclusively for pasteurization of onsite made cider, while I have no idea what they do
off season I should be able to get you some contact information if you are interested !

Well, it all depends on the area you are residing. If it is an industrial there are chances of acid rain or chemicals in the rain. I don’t suggest you to have that water for drinking purpose. Rather you can have that for regular use and that too after quality purification
For me these filters suit your needs.

1. Teflon Filter
2. High Flow Filters

If you want to be more nature specific use solar heater to boil. 

Joseph Warrender : While I do agree with what you are saying, some additional information is needed. Being down wind of industrial areas can be worse than
living along side, !/4 of Californias air pollution comes from china, and much of that is from 100s of millions of three rock fires country peasants are still using !

Recent tests have shown clear glass and many types of plastic bottles exposed to the suns u.v. rays And the simultaneous solar heating to 140dF is capable of
rendering Clear water not contaminated with heavy metals or pesticides safe to drink within ~30 minutes~ Big AL !

You could look at getting a solar Water Distiller, a friend of mine has one and I think he gets somewhere around 10L of distilled water a day.

Not too sure where to put this...
Low tech water filter made from wood has potential to filter out bacteria etc:
http://www.iflscience.com/environment/simple-tree-branch-filter-makes-dirty-water-drinkable

allen lumley wrote:Joseph Warrender : While I do agree with what you are saying, some additional information is needed. Being down wind of industrial areas can be worse than
living along side, !/4 of Californias air pollution comes from china, and much of that is from 100s of millions of three rock fires country peasants are still using !

Recent tests have shown clear glass and many types of plastic bottles exposed to the suns u.v. rays And the simultaneous solar heating to 140dF is capable of
rendering Clear water not contaminated with heavy metals or pesticides safe to drink within ~30 minutes~ Big AL !

I believe you are referring to SODIS:

http://www.sodis.ch/index_EN

http://www.irc.nl/docsearch/results?lmt=20&txt=sodis