I have a friend that has asked me to help her manage her 55 gallon aquarium that is mostly populated with African Cichilds. I have kept tropical and saltwater fish on and off for a couple of decades so I am not exactly green, but I have never managed a cichlid community before and I have grave concerns for her current setup.
Tank size: 55g (standard)
Filtration: 1 very low capacity (outside tank filter) that barely exchanges any water...it's just trickle; with poly fiber only.
Substrate: natural quartz
Other items: 2 medium size pieces of driftwood; maybe 12-14"
Planted: no (just artificial)
Current water specs (as of this evening)
Ammonia: slightly elevated 0.25ppm after 10gal water change
Nitrite: slightly elevated
Nitrate: none (some free-floating algae suspension and on the walls of the tank)
PH: 6 (whoa; this really concerns me)
Aside from the 10gal water change; I cleaned all algae off the tank walls and ran 4 exchanges of a vortex diatom over about a 5 hour period; it clogged the filter with debris between each cycle; LOTS of organic waste in the tank; these are BIG messy fish.
Inhabitants: (one crazy collection of novice fish that I am surprised haven't eaten each other:
3 Oscars (3-4")
2 Electric Blue Cichilds (4"); one is very aggressive; the other less colorful, perhaps a female just hides when not being chased by the more aggressive one along with everyone else in the tank
4 Blood Red Parrot Cichlids (2")
2 Gold Gouramis
1 Melanchronis auratus (Lake Malawi)
1 Bala Shark (5")
4 Small Molly's (surprisingly still living and not someone's lunch)
1 Black Skirt Tetra ( 1.5"); pretty beat up
This amalgamation of residents seems to me a disaster in the making.
How would I best transition this tank to a suitable Cichlid community. My friend is most fond of the Blood Parrot's, the Electric Blues, and the melanchronis auratus. My biggest concern is the extremely low pH and how to address that without shocking them to death; I suppose they have just become accustomed to it. The Melanchronis and the Electric Blue's do srape themselves on the gravel, but I can't see any visible signs of infection; perhaps the low pH is just irritating to them.
My suggestion was to move away from the traditional Tropical tank which is what she has now with natural gravel, driftwood, etc., and move to a better substrate to buffer the pH.
My assumption is the large amount of organic waste and lack of filtration and the tank lacking in any kind of bottom feeders to pick up extra food along with overfeeding flake food all contribute to the problem .
So, in short, the fish a quasi-healthy, but stressed, and I need to move them to a more suitable environment with more suitable tank-mates without shocking them to much.