Massive Die-off After Tank Swap

[ArtistGardener]

I had about 50 little platy fry in a cycled five gallon tank for about a month, until last weekend. I set up a ten gallon tank with new gravel, moved the sponge filter, plastic plants and real plants from the five to the ten and filled it about a third of the way with fresh conditioned water. I then siphoned out all but an inch of the water from the five gallon and put that in the ten. I moved the babies next. I waited about an hour and topped off the tank with more fresh water. The tank temps were the same within two degrees at the time of the transfer of fry. The next morning almost all of the fry were wobbling and/or bottom sitting. They have begun dying off in mass now. There are maybe six or seven that look normal and are swimming in the upper layers. What did I do wrong? Tank parameters are normal: 0, 0, <5. Does such a large change of water stress them that much? So disheartening!

 

[mom2reds]

not sure what's going on I would do a 50% water change and leave the lights off .

 

[GreenLily]

This is odd! Was the temperature in the new tank close to the same temperature in the 5 gallon?

 

[Pandicorn]

This is odd! Was the temperature in the new tank close to the same temperature in the 5 gallon?

Yes, he said it was close. I would leave the lights off as well, that may have shocked them.


Cycling 45 Gallon. ???

 

[gilpi]

I had about 50 little platy fry in a cycled five gallon tank for about a month, until last weekend. I set up a ten gallon tank with new gravel, moved the sponge filter, plastic plants and real plants from the five to the ten and filled it about a third of the way with fresh conditioned water. I then siphoned out all but an inch of the water from the five gallon and put that in the ten. I moved the babies next. I waited about an hour and topped off the tank with more fresh water. The tank temps were the same within two degrees at the time of the transfer of fry. The next morning almost all of the fry were wobbling and/or bottom sitting. They have begun dying off in mass now. There are maybe six or seven that look normal and are swimming in the upper layers. What did I do wrong? Tank parameters are normal: 0, 0, <5. Does such a large change of water stress them that much? So disheartening!

Nothing wrong with big water changes unless the water is not treated or dechlorinated when adding.

 

[HeatherW]

I have heard that fry don't do well with tank changes. I was told you need to keep them in the tank where they grow until they are much bigger. I have not really dealt with moving my fry around, but I know there are some on here that do. maybe they can tell you if it is an age thing - the little ones don't handle the move well.

 

[ArtistGardener]

The smallest were definitely effected the worst. I lost almost 30 fry over the past five days. All but a few of those left look and act perfectly normal. I think it was a combination of factors that stressed them. If I ever have to do this again, I would instead transfer most of the water from the original to the new, then transfer fish, and finally add new water very slowly over hours. Lighting didn't change--I had the same little lamp over the five as the ten, plus the tank is filled with floating plants.