Quote Originally Posted by worldcupkeeper
We picked up a fish tank today from someone on freecycle who was moving and couldnt keep them any more. Its a 20 gallon tank with several different fish, some gouramis (sp?) tetras, hatchet fish, a couple plecos, and a few more. She had drained alot of the water out for transportation and when we got home and added new water a few fish started to die. We lost a few tetras and a big pleco (he was my favorite). Could the new water be the cause of the dead fish?

Ive never owned fish and my mom owned fish when she was a kid (thing were alot different then) and we were told to just make sure the new water was the same temp and the water in the tank. Also the fish were all pretty much hagning out at the top of the tank for a long time, my mom thinks it might be from a lack of oxygen, so I added a tube bubble thing and thay all seem to be ok now, except for 2 of the gouramis (sp?) and the hatchet fish. Any help?
The new waters composition was totally different from the old water. You basically did a mass water change. Changing the parameters that severely could cause a dies off. The new water was not conditioned as the old was.

Hatchet fish stay at the top so that would be normal for them.

From the sound of it, that tank had a massive bioload. Basically they were most likely living in sub par water conditions. By changing it, you shocked their systems with the "clean" water.

Tetras can be very sensitive to any changes depending upon what type they are.

My advice would be to add some cycle to the tank and start allowing the beneficial bacteria to grow in the new water. Do not add any new fish and monitor your ammo. Amquel works good at neutralizing ammo relatively quick.

I don't see where you posted about a filter? That would be a must for the load that tank is carrying. A bubble does not actually add air to the tank but rather disrupts the surface tension allowing gas exhange.

As far as lighting goes, I used to have a 20 gallon tall with hard corals in it and some perculas. That tank was lit by a 250 watt 12K MH bulb. The fish had no problems with the intensity of the lighting.

As far as electrical shocks, the malfunctioning item would need to be in the tank and boy you would know when it goes bad. I had a Rio PH go bad once and man, you can feel the current as soon as you touch the water.

Good luck with the tank. Let it stabilize, and be patient, and you'll find it will be a very rewarding addition.