Water for Black moor

Question
I had a Black Moor fish that lived almost 2 months.  A few days before he died, he was really sluggish, and it started when I changed his water.  I do that every other week.  I don't have a filter.  He was fine the 1st few water changes, but the last time, he slowed down and died a few days later.

I got another Black Moor, and he was doing fine for a couple weeks...just changed the water about 20 minutes ago, and now this one is just laying at the bottom of the tank, not moving.

The water is from an outside faucet, and is room temperature.  No chemicals or anything have been added.  Do you know what's causing this?  Is it just a shock of having clean water?  Any help would be appreciated.  Thanks.

I'm just curious because I've changed the water from the same source, the same way multiple times, and now all of a sudden it seems to be killing them.  Not fun.

Answer
Hi Ryan
You said an outside faucet...is it part of your house or another source?  Well water or city water?  

Not meaning to sound like I'm lecturing here...but goldfish really need to have a filter on their tank.  They put out a lot of ammonia naturally through their waste and respiration.  It just helps to maintain everything in the tank properly.  Plus, with a filter on the tank, I recommend changing about 25% of the water once a week.  With no filter, you should be changing about 50% fo the water every few days(depending on size of the tank).  Ammonia and nitrites will build up to very toxic levels very quickly in an unfiltered tank(even filtered if it's not an adequate size).  Not sure on your tank size, but it's recommended for goldies to have a minimum of 15 gallons for one goldfish.  

Now, it's hard to say exactly what's happening without water parameter info(ammonia, nitrites, nitrates, and ph) but if I had to guess based on what you've told me, I would say the first one died from poor water quality-meaning the ammonia and nitrites were probably too high(but I don't know how much water you changed out either so again, just a guess).  Depending on the temperature as well, may have been lack of oxygen(warmer water usually over 80F depletes the oxygen in the water).  The fact he died a few days after the water change, kind of makes me think of the poor water quality.

For the second one, he's reacting pretty quick after the water change.  If you sure there's no chlorine in the water, I would guess it's either temperature or ph shock.  If the water is slightly different in either of those, it stresses the fish and can kill them.

If you can give me some more info, like I asked where the water source is and what kind, what size tank, how much water you changed, and the water parameter levels, that would help a bit more.  

Hope that helps, and let me know on those answers if you can.  Sorry for your fish problems as well, I know, it's not fun!!

Christy