buddy and I about 3 years ago built one that was a lil over 1000 gallons used a whole sheet of 3/4 inch acrylic.tank sat inside garage and we cut it into wall in living room. inside was sealed with fiber glass and **** it was pain chasing leaks. even after it was all said and done and sealed he ended up draining it. the filtration and flow for that tank was expensive would have better to buy one.