hi, well to answer your question. i am not very experienced with breeding bettas. my spawn was rather large. well to me it was large. i am guessing near 200. because of this there was a large difference in size between the smallest and largest of the fry. the larger ones began half eating the smallest ones. (they could not swallow the heads) also i would watch them and i could see that some were not eating microworms and were not growing. i would soon find these dead. about 5 a day. im guessing either they were starviing, not developing correctly or being half eaten. the dead bodies were just one more pollutant. so i began culling the ones that were tiny and not growing as a sort of preventative.
my fry are now a month old. the ones (about 40) i kept in the 10 gal at my apartment are doing well but are on the small side compared to other peoples spawn logs. i will post pics later today.
on a sad note, the ones i put in tub/tank at my dads house are probably dead. i think i moved them too early or the water was not right or both. i do not see any of them in the tub. i also had the 7 biggest in a 10 gal tank outside. i do not see them either. the water is green so im hoping there may be a few hiding but i really doubt it. next time ill prepare differently for a large spawn since ill have a larger apartment.
Thank you. It does seem like a logical reason, less dead fish means less cleaning. I have a 3 week old spawn that is quite large. I loose count at 100 and there are still 20-30 left, so something about 120. So far I have found 10 dead (2 of these where quite large, which had me worried, but it hasn't happened again) and I tend to check 5 or 6 times a day. I haven't really seen a decrease in numbers, though there are some fry that are fairly small.
I have two tanks set aside, one 20 and one 30 gallon, and plan to keep the smallest ones in the 10 gallon they are in now, then divide the larger ones between the other two tanks, to allow them to grow faster. I suppose it's a matter of space and money, I have the tanks and room to spread out the fry, so see no reason to cull so many early on. Though with less space, it would likely be different.
Thank you for the explanation. And I'd like to reserve at least 2 of your spawn :) A boy and a girl, if you don't mind, the parents are just beautiful!