Sand based nest- moisturize and thickness

[Eva]

Hello guys
I would like to make my own ant nest with sand base. I have 2 perspex A4 sheets and I am just about to do frame. what thickness should wooden frame have (internal) for my L. Niger? and how to moisturize it? 
 this is how I plan it. I want to put 2 straws/ tubes with holes where one would be straight and another in letter 'L' shape with some obstructions (red dots) just so everything wouldn't fall to bottom.
Do you guys think it wouldn't flood ants? 
additionally, would just sand do or should I add some peat? I also have some perlite. I have seen one post with nest base where most people preferred sand base. I just want to make sure that my ants don't get buried  

[Black Ant]

A bit of peat would add stability to the sand, as if sand gets very dry it collapses fast. The straws sound good if you just trickle a small amount of water down them. 

[Eva]

thanks
ok so now I know how much water put to not over water them hehe that sounds like watering succulents
are there any ways to water it? it seems to be quite a big issue :/ I am also afraid that top bit might dry up.. I'll just add 3rd straw just below sand

well I have potting soil with lots of peat so would ratio of 3:1 sand and soild do? or 3:2? 2:1? 4:1?

[Jonzii]

It doesn't need to be very wide for L. niger. Mine is 15mm and that is plenty wide enough, even 10mm would be ok. I use sand/loam as substrate, and have had no problems. It is surprising how little water it needs to stay moist.... Just a few drops every week or two.