My fish are too stupid to get along.

Yesterday the tetras were kind of fighting with each other, which I assumed to be because they weren't doing well. Though the stupid water test strips I have didn't indicate any problem, they don't measure ammonia, nor literally most things, so I thought the problem might be something about the water anyway. So I spent the day trying to figure out how to consistently produce water with the same hardness so that when doing water changes the hardness wasn't constantly changing, and as I was figuring that out, one of them died.

So I did the water changes, and then observed them for a while, and noticed that, while before it seemed like they were all picking on each other equally, it was now mostly just one of them fighting with all of the others. So I pulled that one out and put it in a bucket.

Since I can't keep it in a bucket forever, I put it in with the guppy today. At first it was completely passive, and the guppy just stared straight at it for about five minutes, then for maybe ten minutes it did this thing where every now and then it would turn its side to the tetra, and kind of flex itself and expand its fins as much as possible and wiggle like a little idiot, then suddenly swim towards the tetras gills. For the most part the tetra ignored it, but when I finally decided to get my camera to film it, when I came back the tetra had apparently decided it has had enough and now chases it off when it's near.

The four tetras in the main tank go after each other a little, but it seems that this one was the main problem. Hopefully it and the guppy can teach each other to be nice and I can put them both back in the main tank.

Later in the day...

They are getting along better now. The guppy still does his little pre-attack pose occasionally but doesn't seem to follow it with an attack anymore. Other than that they both seem to want to be in the same place and follow each other. I kind of wonder if what he was doing wasn't some kind of mating ritual, as they develop colorful fins presumably to attract a mate, and he seemed to be showing them off to the tetra before attacking.

That video didn't show it but at first he was fully spreading out his fins when turning his side to the tetra, but by the time got around to recording it, he seemed to anticipate being attacked by the tetra and so he wasn't expanding his fins when he did it anymore. Also, when I looked at them earlier today, before they were getting along, the tetra seemed to have learned to recognize the pre-attack pose and would just ignore the guppy until it did it, then chase it off.

I was wanting to put them both back in the main tank, thinking that maybe with the guppy attacking them they would unionize, but now that the guppy and tetra are getting along in this tank I don't know if I should disturb them. Meanwhile the tetras have learned to occupy different places in the main tank and don't do much as they're trying to avoid each other. So the only tetra behaving like a normal fish is the one with the guppy.

I cleaned the front of the tank so here's a picture.

Algae is going crazy in both tanks, so I think I'm just going to stop putting food in them. The fish don't seem to care for the food anyway, I think because they've spent all day eating algae and aren't hungry.