OK, I need some advice in several areas. First, we bought a 55 gallon tank last of July (we have had a 10 gallon for about a year). There were fish with it- 2 Green Severums, 1 Sail-finned Pleco, 1 BN Pleco, 1 Red-finned shark, 2 Yellow Labs, 1 Clown Loach, 2 Do-jo loaches. Using a Magnum 350...