Tank Update with some questions!

[ThatCrazyFishLady]

So after a few weeks of water changes and such, and finally getting some homeostasis back with the new filter, my water is no longer green! All the levels and ammonia are at their best, and my fish seem a lot more active and happy.
Speaking of fish, I'm selling my enormous barbs to a local breeder, opening up so much more room in my tank. However, I do want to get some new fish, but I need some aggressive enough to handle my fish. My accidental dempsey (as he was sold to me as a jewel) isn't the issue in this case, my male Auratus is. He's been more aggressive with my Kenyi lately, putting him in the corners. I want to diminish the fighting, so any suggestions?

Anyways, for a summer project, I want to improve my fish tank's appearance and make it more homey for the fish. I was wondering what would make a natural, cheap hiding source for my fish. Like rocks and such. I'm not big into planted tanks yet, as I have never had one, so I want to stick to things that don't need more care than the fish XD My issue mostly is my large hand-size jellybean cichlid. He's the ruler of the tanka nd likes to hid the most, so I need some ideas...
And I'm using gravel for the bottom of my aquarium, is this really the best to use with cichlids? Is there a cheaper alternative or anything really?

Thanks for all the help!

 

[KcMopar]

More hiding spots will help in most cases with like species, more on this at the end. An easy cheap way is those tan potter pots. Good alone or put rock on top of them. Gravel is ok for cichlids although I like mine without for easy vacuuming on water change days. Dont worry about the decor to much as they will make it how they want it if they can move. Just focus on hiding spots.
As a side note your Africans (Kenyi) and new world cichlids will never get along. They both have different ways of showing aggression and this instinct cannot be changed. Its best to separate your Africans from your NWC's.