We presently have BRIM media over coarse aggregate of sand and pebbles in a 200 litre drum. Well water is pumped into this drum and the clean filterate from the bottom goes into our water tank by gravity. However this installation is over 10 years old and I think the BRIM media is not effective. If simply changing the BRIM media should resolve the problem, I will try that. I am not sure that this is the best solution since most vendors I call are only keen on selling a more expensive solution involving tanks and pumps. I would like the opinion and suggestions from other residents in Chennai who have faced this problem and have found an economical redressal to it.