dawgdude;421753 wrote: No, different socket and the ballast will only fire the correct wattage bulb. And a 250w HQI would cook a 28g tank as well.
Skimmer, I would say a HOB Aqua C Remora is your best bet. For power heads, I would do either a single Koralia 1 or two MJ 1200 with the tip cut off and holes drilled in the bottom intake to increase the flow. Google Maxijet 1200 mods for more info if you want to go that route.