I did experience this once in my other apartment (different city). The water was so f*cked up, my plant was just looking horrible. Symptoms included yellowing of top leaved first, then of all leaves, loss of stability in the stem, bent leaf stems and curled leaves. After it died i grew another (same strain) in the exact same conditions, determined to find out what the hell was wrong. I saw a thread on some forum about chlorine so i figured, boil the water, then cool it. The next grow had no problems whatsoever. I don't live/grow in that apartment anymore because everything is just messed up. The air is polluted, water sux and the electric bill unbelievebly expensive.
This procedure of eliminating chlorine is very useful in cities where the water is treated and people dont wanna waste money on buying water. I feel it's a useful step in eliminating any impediment that could keep your plant back from reaching its maximum potential.
You're one of the lucky ones if you can say that tapwater doesn't affect your plants and you can actually DRINK IT! Seriously!