It's really hard to tell from the video but it's possible that it has an air bladder problem, or something else. How are the fins on his side? It's possible that another guppy may have nipped them causing him to lose some control. Maybe he's just different? It's hard to say. If he's eating fine and seems healthy I wouldn't worry about it.
From what I can see he doesn't have an air bladder problem. I don't even know what a fish with an air bladder problem looks like. His fins seem to be all there. I put some food close to him but he wouldn't touch it, but I did notice a small amount of poop hang from his backside today.
What are your water parameters? Note that this part is very important.
Well I checked that last night and the parameters are way off then usual.
I did a PWC exactly 1 month ago and my parameters were, (before the PWC)
ph=7.6
Nh3=0
NO2=0
KH=150
GH=320
29Gallons
When I did the water change I added DI water because I wanted soft water and a PH of 6.5. I added about 10 gallons of DI water at,
PH=6.0
KH=30
GH=60
After that I didn't check the water to see if the DI water actually lowered my ph. I checked it last night and it was at,
PH=8.0
NH3=0
NO2=0
KH=170
GH=280
I thought that adding a lower ph,kh,gh water would lower my ph but I guess I was wrong. So I decided to leave all the water and not remove any. I added 5 gallons of DI water with a drip system at,
PH=5.8
KH=40
GH=20
Today I will check my parameters and see where they are at. Then I'll remove 5 gallons from the tank and add another 5 gallons of DI water to it. Right now I have the 5 gallons of DI water prepped at PH=5.8,KH=40,GH=20. I'll change it depending of my readings after another water test today.
You say its right when you turn the light on. Could it be that he is being blinded from the lights and is freaking out. Maybe he needs some tinted glasses :biggrin:
That might be it. During the day he is fine though, when the lights are on normally.
I did notice another odd thing today. All the other guppies have fully black eyes (as in you can't see their iris or the iris is covering the entire eye) and the guppy behaving weird you can see his iris perfectly. Is this normal? How should guppies eyes look like?