I bought this relatively expensive implant for 12000 caps and it doesn't appear to do anything as far as I've seen...

By it's descrption it is meant to remove any radiation taken from drinking an irradiated water source.

However you still take +1 radiation per second when drinking from pretty much everything therefore is it just broken?

I took some screenshots of it:

http://cloud.steampowered.com/ugc/541776341441715449/962E8D294652768BB95A86C169FB26DE9315FA83/

http://cloud.steampowered.com/ugc/541776341441716202/3E43FEE9FB1D2E274A688F4609EF72A9098DA290/

Does it actually increase your total though?

This, It might just be the game showing the icon on the screen. IMO some of those implants are not wort it in the first place. That one in particular, as well as the 20,000 cap implant.

yea, pretty sure its broken.

Looking in the Geck, the implant only applies to bottled liquids.

Useless implant, IMO. Very few locations in the game or the DLCs where radiation is a major problem, and with all the RadAway and doctors around who can remove your radiation for 50 caps (or in the case of The Sink Auto Doc, for free ), even those places aren't a big deal.

Yes, it does increase my total rads level.

It does appear to only work on bottled water, which makes it entirely useless since the vast amount of radiated water you come across is from water fountains and bathroooms.

Oh well I bought it just because I wanted to have all of the implants, but maybe it can fixed with a mod or something.