Questions on tank
 

Should I buy a 422 tank with only 8mm glass. Is It safe to use? Will anyone of you be willing to use such a tank?

12mm would be a save bet lol

so is 8 mm not recommended?

If I am not wrong, I ever used 4x2x2 with 6.0 mm thickness, but not safe for aro.

I believed those normal 4x2x2 tanks should be 6.0 mm too.

Depends on what fish you keeping, not suitable for aro though:)

422 if custom make usually 10mm will be recommended ..8mm should be ok if u are not keeping big monster fish . Jus make sure the silicon is in gd condition.. And have full top bracing.

what if i m keeping a pair of motororay and a few smaill IT?

Still think 10mm will be better than 8mm. Although these fishes will the bump the glass, but still it's better for a 10mm tank as the water pressure is another factor.