Been a while... out of the 10 or so harlequin I bought last time, only one survives, I don't know what killed the others, but one by one they died, sometimes spaced out by days or weeks. Sp,he's alne there, for now.
The fight against cyano has been dragging on for months. I finally seem yo have found the correct light timespan, and after adding a pump for more water agitation, it's been a whole week and not a trace of it.
Added a few more plants, both planted as well as floating one, and for thr first time in a long time, they're also staying well, not withering and dying off.
After much reading about the cyano, decided to add a second filter to help the water movement.
It seemed to make a dent, but did not eliminate it, as it happened after the pump was installed.
Next week I'll remove the second filter and keep an eye for the cyano....
If the tank holds, I've made up my mind: I'll move the plants and deco from the 29g tank, and of course those fish (3 remaining OG neon tetras, they're at least 5 years old now) 5 cory, 2 guppy, 3 ottos and 12 harlequin. Bought those 12 small, they have been there for 2 weeks now, look great and growing, and will be much needed company for the other guy in the bigger tank.