waterdrop
Enthusiastic "Re-Beginner"
The pictures of the filter certainly look like an Aquaclear mini/20 model. I use the same thing on our quarantine tank and it was definately slower to fishless cycle than mid-sized external cannister filters. I think on very small filters the chunks of ceramic can't really form a "bed" that slows the water enough (dwell time is an important filter design parameter but with very small designs you've more or less hit the limit I think.) Thus the surface areas of the biomedia are left a little "cleaner," offering less ammonia and oxygen to the biofilms in contrast to slower filters where the effective concentration might get a slight bit higher.. anyway mostly just an idle thought. For me this type filter did eventually reach and meet it's qualifying.
At the point you are now potentially reaching (little 0.25 blips of one or the other, but usually nitrite at the 12 hour test) you really begin to have the option of cutting it short and doing the first stocking. We rarely see any bad spikes post-introduction when a cycle has gone this long and is fading down and you can easily change water in a small tank like that. Additionally, it's really only full or overstocking that would likely send you into spikes, not a more typical under-stocking if that's what you're planning.
~~waterdrop~~
At the point you are now potentially reaching (little 0.25 blips of one or the other, but usually nitrite at the 12 hour test) you really begin to have the option of cutting it short and doing the first stocking. We rarely see any bad spikes post-introduction when a cycle has gone this long and is fading down and you can easily change water in a small tank like that. Additionally, it's really only full or overstocking that would likely send you into spikes, not a more typical under-stocking if that's what you're planning.
~~waterdrop~~
