drilling of tank, installed painters tape to do layout on, installed painters tape on the inside below drill location to reduce chance of chipping and piece of glass falling through. Put a towel on the bottom just in case the slug of glass did fall through so it would not crack the other sidea after you have a grove started remove template install plumbers putty and fill with water to keep the bit cool
Started putting together the 20G long sump. 3 pieces of glass 9" x 11.75 and 1 piece 10 x 11.75 here is a rough sketch someone from brs helped me with. The piece noted as 11.75 high actually needed to be 10"