aquarium (water behind glass)
I have one idea for my map, and the idea is aquarium, I mean the water behind glass, so you can swim up to the ceiling inside that aquarium. The only problem is, that I can't get it look like it must. I have made a box straight line with the area inside the aquarium glass, with texture Nodraw. It's besides wall so only two faces need water material, the top one, that I got work like normal, but the front side of the water behind glass... I have tried to apply water3_exp and water3_beneath to it, but in game it shows as nodraw, I mean it reflects everything like nodraw material. 
Have you tried NOT using nodraw textures?
Leave the side of the water brush facing the window textured with nodraw and tie the brush to a func_water_analog entity. That will get rid of the rendering bug, but it won't look as nice as 'real' water.
Also, most water materials don't work with it. The ones that I know that will work, are nature/water_movingplane and nature/hazard_liquid (the goo from Portal).
Optionally, because the water is an entity now, you can have it drain out of the room via a trigger 
Other Portal 2 maps: Medusa Glare
Portal 1 maps: Try Anything Twice | Manic Mechanic
that works, I can swim on it and no nodraw problem, but it looks like the air thru the glass wall. and the top surface looks unnatural blue and solid
Yes, it definitely doesn't look like the real thing. You can try to colour the glass or do some lighting magic to create the illusion of water.
(remember the part from HL2 where you are dropped into a manhack-infested chamber which floods with water? The water there also doesn't look nearly as nice as the normal water.)
Other Portal 2 maps: Medusa Glare
Portal 1 maps: Try Anything Twice | Manic Mechanic
Yeah, the water_analog entity is the only way to fix the rendering bug, or to make water move. It needs that specific water texture that uses a specific water shader. Normal refractive water doesn't move in the Source engine, who knows the fuck why, but it doesn't.
Your best bet is to use water_analog to get rid of the rendering bug, and color the glass brush using the rendering options.
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