BN fry sensitivity

[lilu]

Hi Everyone,

My BNs have begun spawning on a fairly regular basis, the largest fry from the first spawn are about half an inch to 3/4 inch long and the youngest just left the cave. About a week ago I moved them into a new tank and they've continued spawning, the fry that moved with them are also doing fine. I have so many fry and because of the fights between the older fry that I posted about earlier I want to set up a grow-out tank for them till they get big enough to take to the LFS. I set up a 10G with a hang on the back breeder box, put the very young fry in the breeder box and some of the older fry in the 10G with HOB filter, heater and some floating plants. However, none of the fry that I've moved have made it. The ones that are in the original tank are doing very well, the few that found their way down the overflow into the sump are also doing well hanging out with the shrimp in the refugium but I cannot keep the ones I remove into the growout tank alive. Are the fry so sensitive that I should wait till they get older before trying to move them?

[FishnFins]

I would suspect water quality, is the tank or filter cycled? I would put the exact water from the main tank into the 10 gallon so there is no shock also make sure that the temperature matches.

[JamesFish]

Try a 50% waterchange on the new tank with 50% fresh water and 50% from the old tank for a few days. The fry themselves are not overly fussy but wipe outs do exist due to lack of food and heavy feeding doesnt help a tank cycle.

[lilu]

Thanks for the comments!! I'll try the water change, with new and main tank water. The filter sponges come from a cycled tank, but I also added extra bacteria. The original water was from the large tank but subsequent water changes have been with dechlorinated tap water - with 10-20% per day there is probably very little if any original tank water left and it's all tap water. The main tank get plant fertilizers since it is moderately planted but I thought would be better to omit that from their grow-out tank since the duckweed doesn't really need them. I'll go back to slowly getting them (new batch) accustomed to tap water (lower TDS but slightly higher KH and GH than the main tank).