Why does my fry tank fail...

[corycrazy]

I have kept corys since last september,with my first being Trilineatus,which spawned with a week,they hide their eggs well,but only laying on average about 10,most i think was 16 eggs.
The very first 8 eggs hatched and all these made it to the 3 month stage,then unfortunately i slowly lost 4 of them,the other 4 are thriving in my main tank now and i recently added 4 more juvis.
I started keeping a record when they started laying again from November 09
Here's what they've spawned since...
1 fry hatched 1/11/09
13 fry hatched 6/11/09
8 fry hatched 8/11/09
10 eggs 13/11/09 eggs hatched 18/11/09
10 eggs 18/11/09 9 eggs hatched 22/11/09
10 eggs 22/11/09 9 eggs hatched 27/11/09
1 egg 27/11/09 hatched 1/12/09
10 eggs 30/11/09 hatched 5/12/09
14 eggs 4/12/09 hatched 9/12/09
11 eggs 8/12/09 hatched 13/12/09
12 eggs 11/12/09 12 hatched 16/12/09
3 eggs 14/12/09 hatched 19/12/09
14 eggs 18/12/09 hatched 23/12/09
12 eggs 23/12/09 hatched 28/12/09
5 eggs 28/12/09 5 hatched 2/01/10
6 eggs 1/1/10 2 hatched 5/1/10,4 hatched 8/1/10
16 eggs 6/01/10 hatched 12/01/10
11 eggs 12/01/10 4 hatched 17/01/10,7 hatched 18/01/10
8 eggs 17/01/10 8 eggs hatched 23/01/10
8 eggs 21/01/10 8 eggs hatched 27/01/10
15 eggs 29/01/10 15 hatched 5/02/10
1 egg 7/02/10 1 egg hatched 12/02/10
6 eggs 12/02/10 6 hatched 18/02/10
7 eggs 18/02/10 7 hatched 23/2/10
12 eggs 23/02/10- 3 infertile,9 hatched 1/3/10
13 eggs 10/03/10- 2 infertile

Now in theory i should have had tons of growing fry by now,but they kept dying in the fry tank,no matter how much i kept the tank clean,for the past 3 wks i have kept the remaining fry (17) in a breeding net at the top of the main tank and they're doing great!(touch wood) ,i would love to give them more room in the fry tank but i'm afraid they might die...
Will they grow just has well in the net?

Thanks

[Coryman]

I think before anything can be determined you will need to give us some information.

1. Tank size
2. Water parameters, ph, GH, KH, Temp.
3. Feeding regeme.

Also there are two stickies at the head of this section dealing with Cory health and egg/fry raising.

Ian

[corycrazy]

The fry tank is 24 litre,unsure on gh or kh unless i buy the kit.
Ammonia 0,nitrite 0,nitrate 10 & ph 7.8,Temp 23 Degrees. -these were the constant readings on the fry tank when it was set up,with a air driven sponge filter.later replaced by a mini elite filter has i got a nitrite spike,so replaced the sponge with mature media,the stats stayed at zero after that.

I use to feed them a small amount twice a day either microworm,firstbites or defrosted bbs.

I done regular 50% w/c change daily,cleaning the bottom and stirring the layer of sand,and temperature matched with dechlorinted water.

But i was still losing them on average 2 a day ,going from 60 + fry at one time down to 8 fry,thats when i decided to move them out of the fry tank into the net breeder,that was 3 weeks ago,since then i've only had 2 deaths...
So am i doing something wrong?

The stickies are fab with lots of info thanks

Thanks

[inkyjenn]

are you keeping a substrate in your fry tank? im new to raising cory fry (this is something like my fifth attempt at it so take my advice with a grain of salt). i had 100% failure prior to adding some sand from the parent tank to a breeder box that has remained in the parent tank near the output of the filtration (the tank has a built in filter in the back). i think the amount of water movement coupled with mature sand (with lots of nibblets for the fry to munch) has helped significantly. prior to this, ive been able to keep the fry going just past the yolk sac stage, and then they died in droves. this time at least half are doing really well. ive used no microworms or baby brine shrimp; ive been using crushed algae wafer (crushed to a powder) and my own recipe for loach food that has been defrosted and sucked up into a pipette several times to make a snowglobe effect. the fry get very animated at feeding times and i get to watch their little bellies get quite fat.

for what its worth, getting your fry to the 3 month mark is good. but why are you leaving them in a fry tank that long? are the adults in a community tank? my adults are in their own tank at this point and once these guys hit about the month mark i want them to be in with them. i think it might help?