Well, now, science class is in session lol ...
Three main Cannabinoids in Cannabis are THC, CBN and CBD
Let us start with CBN, which may very well be water soluble (I'm not 100% sure on that one): CBN, also known as Cannabinol, is a
non-psychoactive cannabinoid found in the hemp plant Cannabis sativa. It is an oxidation product of tetrahydrocannabinol (THC).
Now, THC: Simply put, it's not water soluble
And finally, the issue you are addressing, which I am also by no means 100% on, CBD: Or CBD, also known as Cannabidiol. CBD is the Cannabinoid that causes the couch lock effect you speak of, although it has been proven that depending on ratios it can actually increase alertness. It is also offers a lot of potential medical benefits, as does THC, but not so much CBN. Anyway, onto the issue of losing CBD in a water cure...
Cannabidiol is
insoluble in water but soluble in organic solvents. At room temperature it is a colorless crystalline solid. In strongly basic (Alkaline) medium, and the presence of air it is oxidized to a quinone. Under acidic conditions it cyclizes to THC.
So as long as you're using fairly fresh, pH 7(ish), relatively chemical free water, the CBD and THC are insoluble and therefore will not be lost. These are also the 2 main Cannabinoids that effect the brain.
How ever it is possible that a water cure will lose the CBN, which although it does bind to the CB1 and CB2 receptors in the human brain (less so than THC), it doesn't appear to do a whole lot else that we know of, how ever it could maybe have something to do with helping out the CBD bind, as CBD does
not bind to the CB1 or CB2 receptors at all unlike its Cannabinoid friends.
Hopefully that's not too confusing, I got a bit side tracked from the issue itself I think haha, if you hav any questions, just ask and I'll try clear them up.
Cheers all!
P.S - Due to the fact that
CBD cyclizes to THC under acid conditions, using naturally acidic water may possibly? Remove the couch lock effect and make the high a lot, well
higher haha, it may provide a more psychoactive, THC high (clear/cloudy trich high). No evidence to back that up, just an after thought.