MX, in my L046 hatchery box, I divert a small outlet water hose ( you can use the 6mm air hose ) into the hatchery, this is to ensure clean and oxygenated water in the hatchery. The inlet of the water hose can be inserted into the outlet of your rainbar or outlet of your cannister filtration system. I have done this arrangement and my fries KO rate cut down quite a lot ! !
