My 60 litre/15.5g Pygmy Corydora colony tank
Tank was set up two years ago, stocking and scape has changed several times, but most recently it was my soft water tank for otocinclus and pygmy cories. I had seven pygmies with plans to get more (stores having supplier issues due to covid/Brexit); but they took matters into their own hands and started producing more themselves... Many more! They must have started spawning in April, since I saw the first 4-5 week old babies in early May, and they haven't stopped spawning since
Tank used to be a mix of my tapwater (253ppm GH) and rainwater I collect and store. 1/4 tap, 3/4 rain. When I needed to add male guppies, I gradually adjusted it to a 50/50 mix, so the GH and KH are now at the upper end of the range for otos and pygmies, the lower end for guppies; but still within the ranges for both.
Current stock;
Eight male guppies - the last ones from when I was breeding them. The retired older males and two that were born with swim bladder problems, but they manage okay so I've kept them. Plus a couple of pretty young males that I couldn't resist keeping!
Three otocinclus - Used to have more but lost the odd one here and there, I think because I got them before I knew how important GH is, so they lived in hard water for too long. Tempted to get more because they do well in here otherwise; always active and have nice round tummies, often hang out and sit with the cories etc, but wary of getting more right now and overstocking.
Unknown number of pygmy cories! I did have seven adults, I can now count at least 23 good sized ones, but there are always fry and small babies hiding under leaves and in plants! Impossible to get a head count when there are so many hiding places and a lot of thick planting.
Some Malaysian Trumpet Snails and a lot of tiny pest ramshorns.
Substrate
Unipac Silver Sand at the front and to the right, smooth gravel at the back with the main plants in.
Hardscape/decor - Some small river stones, bogwood, a slate cave, Indian Almond leaves, alder cones, other botanicals when I can.
Plants
Vallis, siamensis 53B, l.sessiliflora, frogbit, crypts, java moss and moss balls, a few more I can't remember the names of, lol. Always want to add more, and pick up new plants occasionally.
Ferts: Rarely... when I remember to add them! Root tabs under the heavy root feeders, using TNC root plugs now, but I also like the Tetra Crypt tablets, broken up and dotted around. Have used Tetramin liquid ferts before, currently using TNC liquid when I remember. Not often enough, but plants seem to be doing well enough without much dosing.
Filtration
Tank has both a marina brand HOB filter on one side and a double sponge filter on the other side, which has compartments for ceramic rings.
Feeding
Usually twice daily, a lighter feed in the am of Bug Bites Microgranules, or live microworms/banana worms, then in the evening one of a variety of small sized frozen foods. Usually cyclops, daphnia, moina, krill, mosquito larvae etc. Things that are enjoyed by guppies but also small enough for pygmy cories tiny mouths.
I often find seed shrimp and other small micro-organisms in the water/detritus I remove during water changes. I think the leaf litter and mulm encourages these, and they are probably what the tiny, insect-sized newly hatched pygmy fry have been mainly living on, so I add fresh botanicals often and encourage this. Hey, free fish food!
Maintenance
50% water change at least once per week, usually twice, depending. Plants usually need maintenance and trimming back every fortnight, so I'll do a substrate clean and W/C any time I'm mucking around with plants. I usually only clean half of the substrate per water change, the left side of the tank one time, including rinsing the filter media in the HOB. Then the next W/C day I'll gravel vac the right hand side and rinse the sponge filter out.
Parameters
Remain very stable, with ammonia 0, nitrites 0, nitrates 5-10ppm. Haven't seen the tank go above 20ppm in years, I think because the plants do the heavy lifting, while the filters and substrate are also well established and can handle any other waste. I maintain weekly water changes even if test results say I don't need to, in order to clean the substrate and to keep the tank water chemically close to the source water, and avoid old tank syndrome.
Thank you for reading all this, and good luck to everyone who has entered
