[Pavel Chaloupka]

The rounded jar and stearing is a very good idea 😉 . I never had them becouse I stock these jars with killifish fry in bigger tanks that have heaters and cover to maintain the temperature stable. Also I mostly raised very litlle fry of each species so I use 1 liter jars and than move the fry to bigger jars and than to small 5 liter,8 or 10 liter tanks to still be able to maintain the density right for them to feed well.