I've kept freshwater aquariums of one sort or another for 40 years now. I've settled on keep African Dwarf Cichlids from Lake Tanganyika. Being dwarfs, they all stay about finger sized which lets you have a more diverse tank. I have a 58 gallon setup 36"L x 21"H x 18"D. Im using crushed coral sand because the water in Lake Tanganyika is hard alkaline: pH 7.6-9.0, GH 12-20, KH 14-20 water. These fish prefer rocky bottoms and do a lot of digging. I used Type-A alkaline granitic rocks I collected myself from my college days (I'm a geochemist). The coral is also nice because calcite is softer than glass and so it does not tend to scratch the glass when scrubbing off algae (and entrapped sand) from the glass. I feed them Spirulina algae cichlid food.
Lets see I have...
4 Juliochromis marlieri (checkerboard black and white)
2 Julidochromis ornatus (horizontal black stripes top of fish)
4 Neolamprologus cylindricus (vertical black stripes)
7 Neolamprologus Leleupi (bright yellow. two breeding pairs, both are tending numerous (10-20) fry at the moment)
4 Clown Loaches
2 Australian Rainbow fish (quick target fish)
2 African Kribensis
2 Paradise Fish (tough enough to cycle a tank, hang with dwarf cichlids, and they hang around high in the water column)
1 Chinese Algae Eater (had 4 but cichlids hate scavengers and try to kill them)
I have a picture of the tank over at 2cpu... http://forums.2cpu.com/showthread.php?p=557400#post557400
Last year I used a 1/6 HP pump and 3 feet of 6 inch transparent schedule 40 PVC to add a fluidized bed filter. I pull water from the tank, fluidize a bed of crushed coral which stands to the right of my tank, and then it goes through a UV sterilizer before return to the tank. I also have a couple powerheads running undergravel filters and a couple air stones to break up the water surface and prevent filming. The fluidized bed looks really cool and is in constant motion. I've toyed with putting an LED inside the bed for effect. I'd like to figure out a way to reduce nitrates without doing water changes. I keep reading about these sulfer and limestone based anaerobic nitrate reactors the salt water guys are using and wonder if they really work. I use fluorescents but am thinking of building an LED array lighting setup. I'd also like to implement a moon cycle with LED's.
I'm Keeping an eye out locally for the following...
Cyprichromis leptosoma (colorful surface fish)
Neolamprologus brevis (tiny shell dwellers, quite droll)
Julidochromis regani (horizontal black stripes all over)
Neolamprologus buescheri (wicked cool looking, never seen one alive)
Julidochromis transcriptus (sort of a blend between ornatus and malieri)
Neolamprologus tretocephalus (broad vertical black and white stripes, panda bear eyes)
Neolamprologus brichardi (like lelupi but Lyretailed salmon colored with pale blue highlights on fin edges)
Altolamprologus calvus (vertical black and white stripes, very compressed body hard to see face on)
Altolamprologus compressiceps (similar to calvus but bulkier)
Cyphotilapia frontosa (like trets but bigger but grow slowly)
If you plug the names into google images you can see what they look like.
Edited: to add fish I forgot.
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