I've had my fish tank for alsmot 15 years now and my guppies are always having babies. But this last patch of fry (23 in total) only grew half of the size of what they were born. Both parents are fancy guppies. Those fish are now 4 months old so I figured they won't grow much more...if they do at all.... I asked on a local petstore and they told me miniature guppies do exist. is that possible? 50 gallon tank with 10 more guppies other than the 23, 4 month old once