Build quality looks great so far mate well done. i don't think it would hurt to add another supporting pilar in the centre ( pic 1 ). obveiously this limits your accessablity to the sump but i wouldn't trust that kinda weight over 6 foot without one. i don't know what your plan was with the access holes, were you gonna have like hinged cupboard doors or slidey ones or what? This tanks gona be a right beast when its done. 







