ok but the top may have to support the other viv slightly? and i work in mm! thanks for all your help! 6x4x2 will be big enough right? some say 6x3x2 some 6x3x3 some 6x2x2 some 7x3x3 some 8x3x3 and some 8x4x4 and ive even seen 4x4x3! these a from care sheetsDubya said:Thick on the bottom to support lots of bedding and heavy basking rocks.