A surprising update on my 80 litre / 20 gal tank from Maidenhead Aquatics. A brief summary for those who (understandably with such a big and busy thread) forgot:
24" x 12" x 18" (roughly), set up with heavy blackwater for south American species. This is achieved with Indian Almond leaves and driftwood.
5 x Black Phantom / Columbian Tetras
7 x Glowlight Tetras
7 x Neon Tetras
1 x Bristlenose Plec / catfish
I seem to have lost a few of the little fish during cycling (never found any bodies, mind) but the rest are thriving now.
With the original setup as supplied by Maidenhead (a tiny Superfish AquaFlow 100 internal filter), ammonia was always around 1-2ppm and nitrites were borderline dangerous to the point of using API salt to help the fish survive the effects. After persevering for a few months I did a 100% water change and bought an Aquamanta EFX 1000 external filter about three months ago. Overkill, but better than the opposite. I set it up following PondGuru's video, with ceramic rings in the base then three foams (coarse, medium, fine) topped by a polishing pad / filter floss in the bottom tray, and 2KG of Biohome Ultimate split between the top two trays. Overkill, but again why not? I also used PondGuru's gel bacteria balls in the filter itself, as well as a dose of Seachem Pristine to be safe. There followed an almighty bacterial bloom which took a week to settle, but the water was down to safe levels almost immediately afterwards.
I have been busy (and ill) for a month or so, and not really done much except feed the usual tiny pinch of New Life Spectrum every couple of days. As such I was expecting a water nightmare today now I've finally gotten around to the cleaning the poor little buggers. They haven't even had a water change in all that time. So I tested the water (API master test kit) and got:
pH: 7.2
Ammonia: 0ppm
Nitrite: 0ppm
Nitrate: 0ppm
(Sorry for the crappy quality, they're hard to photograph especially on a phone. Left to right: pH, nitrite, ammonia, nitrate).
WTH. That BioHome Ultimate stuff really does work as advertised. I've never even been able to get this little tank to 0 ammonia before with crappy internal filters, but to see
nitrate also at zero thanks to the anaerobic bacteria having already colonised the dense inner core of the BHU? Amazing. I wouldn't have believed if I hadn't seen it myself. In fact I did the test twice thinking I'd messed up lol. So aside from needing a substrate hoover the water is actually pretty bloody pristine, and really validates my decision to go overkill external. Winrar. \

/ Towards the end of the year once the water has gotten 'old' I want to add a pair of blue rams to complete the setup.