We have gotten past the point in the biological filtering where ammonia in the water is high. Now, we have higher nitrites and nitrates are starting to kick in too, and the ammonia is nil.
The other day, I asked Steve to stop and get 2 more neon tetras and 1 more zebra danio. The neons are just beautiful, but oh so little; I wanted to add a couple more to their school. And the zebras were having issues with aggression - I believe we had 1 boy and 1 girl; the boy always wanted to be hanging out with the girl, and she tried to get away from him all the time. I had Steve get a zebra that was more curvy & round in hopes it'd be a girl. I think that's what we got.
The neons that he got were little, like teenage-sized. Their color is beautiful, though, and they easily blended and got along with the other neons.
As soon as I put the zebra danio in the tank, I thought I'd made a horrible mistake. She started zipping around the tank, and the male starting zipping behind her. I had wanted to make the tank calmer not more anxious. The next day, everything settled out. The girls calmly swam together and apart and, the boy didn't harass them and mostly stayed away from them.
As I was looking through past blog posts, I see that I have left a lot out.
When the nitrites came into being back on Feb 24th, the ammonia had spiked. It caused all of the mollies to die: both creamsicle mollies and gold dust, who I thought was a platy, but was really a molly. Bumblebee platy died, and the two baby mollies did too.
That left us with our two-bar platy, 2 zebra danios, 3 neon tetras, and the 4 cory catfish. Two bars was so upset - he had stayed with all of the other fish until they died, and he seemed traumatized; he paced - swimming top to bottom of the aquarium over and over - and wouldn't settle down. That day is when I asked Steve to go get 2 female platys to be his friends (boys fight.)
So now, we have:
2 platys: one two-bar platy (Two bars), one sunset fire platy (the other sunset fire platy died yesterday)
3 zebra danios
4 cory catfish
5 neon tetras.
The sunset fire platy that died was named Damsel; she was pale and looked fragile, thus the name. She lived here for a week or so, but night before last she got a red spot on her side; she was dead on the bottom of the aquarium floor the next morning.
Everything seems to be going well. We still have high nitrites and the nitrates are growing, but still low in number. I am doing 1/3 tank water changes about every other day to keep the nitrites down. There is the brown algae in the tank along with hair algae - the platys fight over the hair algae!
Also, I put back in the medium sized castle decoration that I'd taken out - the catfish like to hide behind things and wouldn't come to the front of the tank; the tank floor was divided between cleaned gravel (in the back) and uncleaned gravel (in the front.) The catfish like to hide behind the castles now and will come forward more.
I also added a bio stone last week. I'm hoping that it helps stabilize the bio-filter.