Recycling water in a flat with restricted space in Mumbai,Maharashtra - Need a low cost, portable filter

I am residing in a Flat(Apartment) and I intend to reuse the water from the washing machine, Wash Basin & if possible Bathroom. To be reused in Toilet & washing of Utensils in Kitchen.

I would like to try out using two PVC Pipes of 4" Dia & 24" length, serially connected,Placed vertically, the first one consists of sand, screened 1.6mm & the second with pebbles approx around 10-15mm size. Later pass this water thru a low cost UV filter consisting of a carbon pre filter. I am ready to redo the plumbing if I get a working system. I have got only one bathroom & One toilet in my apartment.

Will this help in reusing the detergent water from the washing machine, if not I intend to use the water during spinning mode (less detergent in water).

Can this system be used or can you suggest an alternative. Idea is reuse the water from my apartment. But the size of the filter system should be small.  Aim is to reuse & store 300ltr of water, this water will be used in toilet , routine cleaning, Kitchen utensil wash, for potted plants  & my aquarium. 

Awaiting for a working solution, low cost & portable to be used in an appartment Flat


N Srinivas Rao

Mumbai, Dahisar.