Guppy Fry Advice?

[sandyroz]

This is my first time having guppy fry and as of today I currently have 16 fry ranging from 1 day old to 2.5 weeks old. I was wondering around what age they could be placed back in the "adult" tank so as to not get eaten. My biggest concern is that if I keep adding new fry to the fry tank, the older ones will start nipping at the youngest ones. 
 
If It helps to determine their possible growth rate, I have a heater in their tank that is set to 78 f, close to no hiding places, and I feed them several times a day both with specialized fry food as well as crushed up normal flakes for the older ones. 
 
Thanks in advance!
 

 

[Dreamer03]

First, what is the size of the fry tank, because if ti is too small they may have stunt growth. And well I let my fry stay in the adult tank but my tank had mnay planst and other hiding spaces. So I would say in about a month? They should be large enough and fast enough to not get eaten,

 

[sandyroz]

The fry tank is ten gallons and the adult tank is twenty gallons. I just upgraded, hence why I have the ten gallon left for the fry. I'm looking to buy some live plants soon, but that may not be for a month or two so for now I think they are better off separated from the adults. The eldest fry is nearly three weeks and by the looks of it, I doubt he'd be picked on too much in the adult tank but I think I'll leave him for another week or two just in case since I do have a Dalmatian molly nearly two inches in the 20 gallon. 
 
Any idea about when the fry may start attacking the younger ones?

 

[Smelliot]

Generally as soon as they colour up they should be fine - basically as soon as the guppies recognise them as one of their own. Introducing them in whilst it's dark probably also helps aswell as hiding places. You can also use the mouth rule, if it looks like they'll fit in don't put them in. I don't even pull my fry but I have plenty of plant cover and I never lose many/any 

 

[sandyroz]

By color up do you mean their fins and body color such as in a mature guppy or the change from grayish to a shade of pale orange (in my fry at least). I'll probably end up waiting another month or so either way. Thank you for the answers!

 

[fishy_wishy]

What size are you fry? my fry escaped (the hooks fell off) from the breeding need at 7-8mm, all 12 survived