lava rocks? moss wall? best wooden boards for a planted tank?

[KittenFishMom]

I'm thinking about making a triangle or rectangle wooden frame, lined with window screen and polyester batting to hold my growth substrate in one part of my tank, and hide it with rocks and put sand or pebbles in front of it.  

What sort of wooden boards would you recommend? Do I need to boil them first? I would think pine and oak would be bad.

I have been watching lots of videos and wonder why so make people use lava rocks instead of stream cobble stones? It it the weight or the texture or the chemical make up of the lava stones or something else?

I am interested in having a moss wall up the back of the tank. I would assume it would get more even light if the bottom of the wall is set out into the tank an inch of so from the top of the wall. (Like trimming a hedge so the top does not shade the bottom.) How do you keep fish from getting trapped behind the moss wall? What to you recommend to the base material of the moss wall? hardware cloth or netting or plastic needle point canvas? or mesh fencing? Do you put your wall on a wooden or plastic pipe frame? Do you have it stop below the water line, or go to the top of the tank, above the waterline?  Do you need to move your HOB to hang on the side of the tank?

Feel free to pick and choose the questions you want to answer, if any. Also, feel free to answer question that I did not know enough to ask.

Thanks KittenFiskMom

[Flumpweesel]

Wood choice be careful sap can be toxic.

Pebbles Vs lava or dragon rock is just personal choice. I've used pebbles from the beach just cleaned them up and made sure they are a soluble mineral that will affect pH.

Moss walls can take a long time to establish so good luck. 

[KittenFishMom]

@FlumpweeselI may start with a narrow moss wall, then when it fills in, rotate it 90 degrees so it will start growing upward and lower it as it grows. I haven't started, so the possibilities are endless.