So I recently acquired a 220 gallon tank it's drilled with 2 overflows (They look like MEGA Overflows, not sure though). I'm going to running cichlids, jaguar, acouple oscars maybe jack d. I'm going to convert an old tank to a sump I'm just curious as to what size tank would be good. I'm currently looking for a 55 gallon and I'm not sure I'm calculating the GPH correct because I'm coming up with around 1800 GPH. Is this correct. I'm a super noob when it comes to sumps, My last tank was only a 75 gallon and I ran a RENA XP3 on that and it did wonderfully. I just want to get this right the first time. TIA!