Opinion on tank stocking for breeding???

[Coop23]

Hey everyone.
I breed fish and am starting a small business now.
I have 9 tanks currently
-4 20 litres
-2 65 litres
-2 45 litres
-1 30 litre

Just want your opinions on what you would do with each of these tanks to create the most profitable and efficient breeding setup possible. I already have fish stocked in these tanks but just was interested to see what other people would do.
Btw I am only a teenager, but have been keeping and breeding fish for 5 years now.
TIA.

 

[GaryE]

I've bred fish for fun for 30 plus years, with probably 200 species distributed, and when I read your posting, I scratch my head.

Fish.

What is that? Every species has distinct needs, and how you set up depends on:

your water source;
the species you've chosen;
the local market.

With a lot more information, I think you'll get useful responses.