Save your money.
No one I know with more than a few tanks uses any chemical stuff beyond de-chlorinators, plant nutrients and pH buffers except on an occasional basis for specific needs. If you're doing everything else correctly, there shouldn't be any need to develop a reliance on chemical treatments/additives (in your tanks and perhaps elsewhere). Chemi Pure is just "activated" carbon with some absorptive resins mixed in to extend its working lifetime, and like carbon must be continuously replaced. It purportedly lasts longer than carbon but is also considerably more expensive. If you're doing periodic water changes and have a decent filter, you might consider saving saving your money, or simply getting a better/second filter because unless your water us full of stuff that is generally frowned upon/prohibited by public/municipal health officials/authorities your tap water should be fine as well as crystal clear.
I'll lay even money that whatever issue it is that you're having with cloudy water could be fixed with a $2.99 one-time purchase of a foam pre-filter attached to the intake of your current filter.
"As in most aspects of life subject to human control or influence, problems arise - the treatment of cause as opposed to symptom is part of what separates aquarists from mere fish-keepers."
— Causal Mechanisms , Chapter II, Volume II, Encyclopedia Aquatica
