Join Date: Apr 2018
Location: San Francisco, USA
A few months ago I set up a ~4g cube. It currently has an AC20 on the back with just a sponge, though in recent days I have added some carbon. It has a hardware store LED 6000K bulb, with wattage I cannot remember at the moment though it is decently bright, even if this small stank still has some shadows. Substrate is relatively deep with 2" in the front to 3" in the rear, with just rock, no dirt or fertilizer. There is about 1/2 gal volume of drift wood, with moss and one, relatively large anubius, all attached to the wood. As for fauna, there are two African dwarf frogs and 5 celestial pearl danios (galaxy rasbora). I keep the heat at around 78F. pH is naturally low, close to 6, perhaps a smidge higher (getting a new pH meter tomorrow.) I use 0 TDS water and add Excel Flourish regularly -- the tank is algae free.
After about 6 week of running only a Rio90 with everything except the fauna and wood, dropping in a few pellets of frog or fish food now and then. After a couple of weeks I added one, small, low budget (i.e. not one of the celestial) danio. Wait a few weeks. No nitrogen. In fact everything reads 0, including KH and GH. Wait a couple of weeks. Added the AC20 with only a new sponge and removed the Rio. About a week, with still no nitrogen, I gave the cheap danio back to the store and bought/added six of the celestial danios. Couple more weeks. No nitrogen. Throughout all of this the flora look good -- green, strong. Couple more weeks. Suddenly, one danio dies. No idea why. Even dead for a few hours when I found it, it looked healthy. I think it's just a coincidence. A wee later the water looks every so slightly white and milky. I have close to 0.25 PPM NH3. I do a 2 quart water change and add some carbon into the AC20. After a few days it's a little more milky, but not alarmingly so. Close to 0.5 PPM NH3. I do a water change close to 1gal. NH3, maybe back towards 0.25PPM. Still no NO2, NO3, KH nor GH.
I'm 3 to 4 months in and now it cycles? Is that what's its doing? Or...? If it is cycling, I'm wondering if not using the AC20 during the first month or so was a mistake that biting me in the rear? Even so, that was 2 months ago.