My first enclosure - Vivarium build

[Calcifer]

Hello, i am completely new to the hobby and wanted to share the plans for my enclosure to get advises and to check for mistakes that i am possibly making

Species:

Pachnoda Marginata | Zophobas Morio

Enclosure:

i have a fish tank (around 100L) im planning to use 10cm of subtract which is around 30L

i'm thinking about using coconut humus as main content, beech chips for wood content, local leaf litter and some zoo med creatures soil


links to products (its a Portuguese store but you might recognize the product by the picture): 
humus: https://animallux.pt/repteis/solos-substratos/trixie-reptiland-humus-de-coco
beech chips: https://animallux.pt/repteis/solos-substratos/reptiland-lascas-de-faia-extra-fina-10-lt
zoo med creatures soil: https://animallux.pt/repteis/solos-substratos/zoo-med-creatures-soil-substrato-solto
i'm working with national shops so i have limited options
 
i'm thinking about using 10L of beech, 5L of zoo med creature soil, 15L of coconut humus and leaf litter by eye
 
is this subtract good for them? am i using something that i dont need and can make it cheaper? 
 
Questions that i have:
 
i want to keep both species, can they live in the same enclosure? 
i want to use succulents plants as decoration, do they eat them/is it a bad idea? 
should i add springtails?
since i am new i dont want them to breed like crazy and kinda lose control of the situation, i'm thinking about separating them by sex and then only have 1 pair breeding, since the soil of the main enclosure will only be for the grown up beetles do i still need the 10 cm of soil? do i still need wood content in it or do the beetles only eat fruits and vegetables?
does the subtract described above ( 10L of beech, 5L of zoo med creature soil, 15L of coconut humus and leaf litter by eye) work for the breeding box?
 
i'm sure i'm going to have more questions after this one so thank you in advance 
 

 

[BensBeasts1]

I would recommend adding rotting wood, for P. marginata they need amounts in their diet. And I would not recommend adding succulents because they are desert plants. (Z. morio is a forest species of darkling) And any plant you add in will likely be nibbled on. If you really wanted plants perhaps a semi-tropical or temperate plant. 
 

I don’t know much info about the Sun beetles though since I Need permits to get them in the US. So someone Who is more experienced and knows more than me can help more.

 

[Calcifer]

they dont eat the beech chips?

i have some rotting wood that i grabbed from a local wooded area but i have no idea what type of wood is, and i dont know if is the right type for them, i think it was from some coniferous tree and i read somewhere that coniferous wood is not good for them, the wood that i grabbed is completely dry and with no resin left tho, i even put it in the oven to sterilize it and there was no resin leaving the wood with the heat, still dont know if i should add it or not