Need some assistance on a 4x2x2 fixerup tank. It's missing the overflow in the back right corner so I just have 2 holes in the bottom back right (1-1/2 and 1-3/4). The overflow on the back left is still there but the 1-1/2 and 1-3/4 are just holes and there's no bulkheads. I have an extra 29 Gallon Tank that I would like to use as the sump. I currently have a kessil a350w and plan to get one more for this. Planning on Mixed reef and not really big on fish... more on coral. Been doing 2 nano reef's for about 3 years but never even had a sump. Initial questions are do I need both overflows or just plug up the right two holes? If its better to have can I just have TAP (or the like) just cut some pieces in and create one. Is that size sump adequate? Big Thanks for any suggestions you can offer.