Figure 8 swimming up and down the glass

[helicopter]

I just added two figure 8 puffers and a black molly to my 24 gallon nanocube. The two puffers seem to be getting along well and they generally seem healthy. They have been eating a ton (cooked jumbo shrink and pond snails). However, one of the puffers constantly swims up and down the glass at one spot of the tank. He has done it so much that he has started to wear down a tiny white spot on his nose. I checked the water parameters: nitrates, nitrites, ammonia are all almost zero (I had just changed half of the water in the tank a few days ago). The pH is around 7.8 as I have crushed coral in my filter. There are a ton of plants and hiding spots so that isn't really a problem. What could be causing this behavior? Also, will his nose heal? Is there anything I can do to promote healing?

 

[WaterPond]

My old puffer (which was a dwarf puffer) did the same thing alot, but the fact that you aren't seeing any nitrates... hmmm.

did you cycle the tank?

Are the plants that you speak of, live?

 

[helicopter]

Tank

Yes, the tank is fully cycled. All of the plants are live. Some people suggested that he might be seeing his reflection, but he also does it at night.

 

[WaterPond]

could be... i cant be sure though.

 

[ben1157]

I just added two Figure 8 puffers to my 30 gallon and I have one that's doing exactly the same thing though he's not damaged his skin yet. How's your puffer been acting in the days since you posted this?

 

[helicopter]

Better

They seem to be doing better. He has stopped incessantly going up and down in one spot and now explores the entire tank. I think putting plants in the area where he would go up and down at helped force him to stop.