I've had guppy fry in a little breeder in my large tank for about a month now, and they are barely 3/4". Could the small tank size be inhibiting their growth? I have a 6 gallon but it hasn't been running for very long and is a bit unstable. I'm afraid that if I move them into it, they'll die.
Maybe that would be the best thing to do. I first started out with mature media (about 6 months ago), but after maybe 4 months I bought new stuff for it. Right now, it's empty except for one ghost shrimp and a feeder guppy. Maybe I'll put some more mature filter media in it. If I do that, can I introduce the guppies ASAP? Or wait a few days? I'm not an expert on cycling or anything if you couldn't tell. I