5 gallon fluval spec v reef upgrads

Hello everyone! I'm new to thereeftank and I have just recently set up a 5 gallon fluval spec v micro reef. So far everything is great. Water is Crystal clear and parameters are perfect. The only thing I changed is the lighting. I'm currently running a 18"-24" current USA orbit marine led light with a ramp pro timer and controller (witch fits perfect on the tank by the way). So far I am very impressed with the light. I have a pretty big zoa colony,some polyps and a nice toadstoal. At least I think it's a toadstoal. Still don't know the names of certain corals. They seem to love the lighting. Open up every morning and look amazing under it. I have around 7 pounds of premium live rock and about a 2inch deep sand bad of arag alive indo Pacific sand. So my question being I don't know what to do to make this a better tank. I would like some opinions. I was thinking about removing the massive filter sponge they have in the back chamber and putting some kind of protein skimmer in or just buying the after market filter basket and putting in some chemi pure elite and purigen. Idk if being such a small tank (that I don't plan to overstock) I would need a protein skimmer plus I have all that live rock and sand. The water flow on the tank now is minimal with there pump putting out only 85gph. Any suggestions on updating that? I plan on ordering a koralia nano 240gph tonight. Let me know what you guys think. I really love this tank and only want to do what's best for it. Thanks