ive never had a problem breeding any of my pairs and i have had many. i have a pair of managuense that are not the best parents ive had. i usualy sepperate after 4 days of free swimming, the parents tank is at 80 all the time. i have a 20 gal with 2 sponge filters and 1 bubbler. while its unoccupied by fry theres usualy a fish in it to keep it cycled and what not. when i remove the managuense from the parents they go in that tank. it is set to 82 degrees, everything seems fine for a day maybe 2 and the numbers start dropping off until there all gone. any ideas? would water chemestry and 2 degrees kill fry off that fast? i have 6 20 gals that i do the same with other fry and theres never an issue. why managuense? it happens no matter wich 20 gal i put them in.