Zoa wont multiply

[Whiskyclown]

Running 4-6 fish is not uncommon on a nano, it's depends on the equipment. I think the setup is just lacking supporting equipment. @Whiskyclown what is that in the back left of the tank? You said it has another chamber? Im assuming the back right is a HOB skimmer?

I have a protein skimmer on left and on the right have a hob filter with chemi blue pure on it

 

[Wankell]

I have a protein skimmer on left and on the right have a hob filter with chemi blue pure on it

Oh ok, that's not so bad then. Maybe try to run some chaeto1 or toss a mangrove in the tank corner, that should help a little with nutrient export.