Water Filter Service CM - "Inventa" Brand

[ThaiHerbs]

We have a wall-mounted "Inventa" brand water filter system beside our kitchen sink. It is 2 stainless steel tubes 18" high with 2 taps. We inherited it with the house when we bought 3 years ago. All instructions are in Thai and when the taste became noticeable my GF did some kind of back-wash service to it about a year ago (following the Thai instructions) and it seemed to do the trick. But - the taste has once again deteriorated.

I would like a Professional service person to come and do an inspection and advise us on proper maintenance procedures. The only source for an Inventa search came up with this useless website http://www.inventatech.com which seems geared to large industry. I was hoping to find service info online on the model we have.

I may set up my Berkey again (great system btw) in the mean time. Just a pain ordering filters from the US but it does remove fluoride (optional) which I really like and the water tastes great!

Any ideas for service?

Thanks

Doug