Bad water change.

[THE V]

Last night I did a water change on all of my tanks.

I started with the guppy tanks in the garage (10, 10 & 15) and got those done with no problems. I use a python directly from the tap with prime. I didn't have any issues and the fish were all happily darting around the tanks as normal.

I then moved into the living room and did the 125g tank. I had 6 goldfish, 3 rosy reds, and a pleco (ya I know about the pleco but hes one of the oldest fish I have.). I repeated the exact same process that I did with the tanks in the garage and about 1/2 through filling up the tank I noticed that I had an extreme amount of bubbles in the water. Almost immediately all of the fish in my tank started acting stressed. I double dosed the tank with prime thinking that I might have had chlorine hotspot. I lost the 3 rosy reds within minutes.

All of my goldfish were very stressed but especially my large female shub. For a short amount of time she even stopped breathing. I reached in and started moving her back and forth in the water for about 20 minutes until she started moving again. After about 1 hour they all started doing better.

Now the million dollar question is "What the heck happend?!!". The only thing that I can think of is that although they do not generally report it many water districts use ozone to sterilize water. Do you think all those bubbles were ozone?

Just a little ticked off right now. I'm just happy that I didn't lose any goldfish.

 

[Jolt]

Wow that's kinda scary. I have no idea what it could be. But good luck with your fish!

 

[Ichthius]

It's gas supersaturation. It's worse in winter because cold water holds more gas so as it is heated but kept under pressure it supersaturates. The trick is to spray the water into the tank. I have a 3/4 inch pvc pipe that hangs on the tank and hooks to the end of my python and in the end of this I put a bulkhead screen which causes the water to break up and off gas.

Fill the tank slower, spray the water and increase aeration and you'll be fine.

In extreme super saturations situations where you have a suction leak on the intake of a pump you can give your fish the bends where bubbles of nitrogen collect in the fins and gills. You need to only be at 105 to 110 % of saturation to cause damage.

I think this is as much a part of letting water sit for 24 hrs before using as the chlorine issue. With cloramX and spraying the water you can do 90% changes.