I'm going to say she's perhaps 6 weeks old, give or take a week or a few days.
There is a very good chance that her growth may be stunted... The best way to get her to grow is to do some 'power' growing! Through my first and only shot at breeding bettas I found that when out of warm water and when eating less food, bettas stop growing and move through their life cycle more slowly. But, even after a long period of time, if you get them in warm water again and feed them like crazy, the life cycle will speed up again and they will grow to adult size. I dunno if this happened all the time, but it happened with me.. My 3 babies were always on the smallish side, and nearly a year later I put them back in warm water and fed them lots and they grew to be monsters.
So right now, you need to warm her up and feed her plenty of good foods, almost to the point of gut-stuffing her. 68-70 degrees is nowhere near warm enough, you need to find a heater. The Hydor Mini Heater would be a good choice, or the Hagen Elite Mini Heater (25 watts). You'll want to try to keep her water around 79-82 degrees Fahrenheit. Do water changes often, as baby bettas give off a growth stunting hormone, so you'll want to get rid of that. For now its best to not have a filter, just so you can do 100% water changes often so she can grow.
As for food, feed her often, at least twice a day, maybe up to 4 times a day. Hikari Micro Pellets or Fancy Guppy pellets have better nutrition protein-wise than their betta bites (weird!) and should be small enough to fit in her mouth. Freeze Dried or Frozen Bloodworms, Daphnia, Mysis, Tubifex or Brine Shrimp should be good. Microworms are good too, but you might find it easier to hatch your own Baby Brine Shrimp (they should sell eggs at Petco or Petsmart) than raise Microworms, and BBS are a superb food for baby bettas.
See how fat these babies are? Until she reaches adulthood, try to keep her fat like this (well, maybe a little less!).
When you think she has reached full betta size, start feeding her less and cool down her water to 75-78 degrees if possible.
So the three basics are LOTS of food, warm water, and lots of water changes. Hope this helps!
Edited by Suwa, 22 January 2012 - 02:44 AM.
) There were so many other bettas there, some floating and only moving when you moved the cup, some actually nice ones pretty active...but the thought of this baby growing up in a cup just...well to say the least my little sister decided to save her/him...He/she will be living in a two gallon bowl that we have available...we will do 100% water changes and our temperature in here is about a constant 68-70 degrees...should we put an air pump/air stone in there? A few more questions...
