mixed south american tank

Hello everyone, I've kept fish for a long time, but I've never kept cichlids. I've got a new 125 (72" long) acrylic tank on order that should be here for Christmas, so I'd like to order some new fish and get them quarantined pretty soonish. I'm thinking of transitioning to SA cichlids since...

I just got a silver arrowana today and aclimated for over 3 hours before adding it to my 200+ gallon tank. The tank is 8ft. By 21" by 23" strange but that's what it is. I have a 110 gallon sump and my pump moves about 1500gallons and hour. My pH is 7.4 my temp is 79' Fahrenheit. No ammonia no...