So I have had this 20g tank running for about 4 months, Since its my first saltwater tank Its been a learning curve with many fails and lessons learnt but thanks to this forum managed to overcome most of them. I am very new with corals and stuff so can someone tell me if they look ok? and the bubble tip? And any improvements or suggestions about coral placements etc are appreciated. Stocking: Royal Gramma Pigmy angel 2 clowns 1 yellow watchman goby I have the koralia nano 420gph with two hang on back filters, no skimmer or sump but do a 25% water change every week. So far the tank has been perfect for about 1 month with no massive algae blooms and the xenia and GSP have tripled in size since I got them bout 3 months ago.