15 gal eclipse system

[ralphvg]

Walked into PetSmart on New Year's Eve to buy some food for my freshwater tanks and walked out with a 15 gallon Eclipse system that was on close-out for $70. Marinelife claims the system can be used for either fresh or salt. It has a bio filter built into the top, this one came with a decent 50 watt heater and the single bulb is a "natural daylight". I always wanted to try salt--been doing fresh for 30 years. So far I have 20 lbs. of substrate--not sand, a bit larger white peices (already forgot exact name!), 8 lbs. of cured LR. Water and substrate were in by New Year's evening and the LR went in 3 days later. I know I need more LR, thought I go slow with it. Things starting to grow already!

My question is, now realizing that there are much better "systems" to be purchased for filtering and lighting, will I be alright with 2-3 small fish and some maintenance animals, and will I be able to grow anything else besides the LR with this lighting. It is 5 ft, away from a northern window if that's any help? Would a different bulb be better?

Last concern, skimmers. With the top being completely enclosed, it would be difficult to cut the top to add a skimmer as the filter system runs across the back. Is the skimmer a "requirement"?

Thanks in advance.