Hi. I've been keeping fish for a few years now. I have 135g, 75g, and 15g tanks. My 135g houses mostly cichlids with gourami's and an iridescent shark. My 75g houses 5 oscars, 2 firemouths, and a smaller bala shark. My 15g is my fiance's failing experiment in which she kills fish. It's sad but she's determined to make it work. I've tried seeding her filter/sand/water with mine but no success as of yet.