blackwater tank cycling?

[anewbie]

I was moving the orange tetra from the n.t. aquarium to the a. ipiranga aquarium since they were picking off too many frys and took this picture in case there is interest:

 

[MacZ]

Miniature Piranha.

 

[anewbie]

Miniature Piranha.

I suppose but then you have this guy:

 

[MacZ]

hehehehe

 

[anewbie]

Random picture of a 100 (48x24) - well not random - had to do some work on it so spent an hour or so cleaning a few things - the only major change i think from last picture is i had 30 or so ruby tetra - they mostly hang out front but really object to the camera so they scattered as soon as i put the phone up there. Really nice tetra...

 

[anewbie]

This from the aquarium that started the thread - it is now around 3 years old:

The original set of emerald eye rasbora (brevibora dorsiocellata) are still with us but the hatchet fishes and bitaeniata all aged out as well as the coral red pencil fish (n. morthenthaleri). Not sure what to make of those - i had 3 sets and 2 didn't live much longer than a year but the third is still ticking. Currently i have 6 norbert (at least 5 are fine likely 6 but they never developed any colour despite the lovely picture on Tom's website) and i recently added 4 young ladisalo which seem to be fine. I don't expect much hostility and so far (4 weeks) i've not noticed any issues - there is substantial room in the back the fishes rarely utilize. I also added 6 junior tetra (h. robustulus) to get a bit of experience with them and there are some cardinals i added 18 months ago that were meant for the discus aquarium but came in way too small which is just as well as i have discovered my discus will eat adult cardinals just as easily as small ones. I dont' really plan on helping the norbert if they breed but if the ladisalo do breed i'll try to give them a hand with live food.

Also if the ones i put in the 15 (i believe a different species) fail to breed after 2 or 3 months I might try them in there.
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What actually prompted me to make this post is I've had this problem will occasionally for no reason anubias will just up and rot after a few years - sometime the plant will die or sometime it will do this:

You can see the rotten portion going straight back - but what shocked me is how quickly this new growth has taken off - jsut a couple of weeks ago it was 2 tiny leaves - now it looked like it jammed in a year of growtih in 6 weeks. No clue what triggered the rot and no clue how it was able to regenerate so fast given that the 95% of the plant rotted.