[avraptorhal]

I just removed the second HOB filter after installing canister. On the second day two of my platies started going to the top and gulping there. I assumed it to mean low Oxygen levels. Didn't see any similar behavior in the gills, maybe poor eyesight (LOL). I installed an air stone and pump. This is the third day and they have resumed their normal behavior being lazy until dinner (mine) and then playing around.

So, it sounds like I guessed right.(?):-?

 

[Byron]

We need to explore a bit more. While the symptoms you describe would be caused by a lack of oxygen in the water, they are also (and much more frequently) the sign of something toxic in the water.

What is the tank size?
What are the fish species, and how many, in the tank (total)?
Are there live plants?
How often are water changes performed, and how much of the tank's volume?
What is the temperature? pH? Nitrates?

Byron.

 

[AbbeysDad]

+1 What Byron said.

Although we might conclude that the new canister filter return does not move surface water like the HOB(s) did and this has resulted in less O2 xfer, we shouldn't jump to conclusions. There could be a negative water quality issue that shouldn't be overlooked.

footnote: Just my $.02, but although it typically 'dosen't hurt' to have air stones or bubble bars, they are very rarely required so long as there is surface water movement/circulation.

 

[avraptorhal]

We need to explore a bit more. While the symptoms you describe would be caused by a lack of oxygen in the water, they are also (and much more frequently) the sign of something toxic in the water.

What is the tank size?
What are the fish species, and how many, in the tank (total)?
Are there live plants?
How often are water changes performed, and how much of the tank's volume?
What is the temperature? pH? Nitrates?

Byron.

29 Gal

2 sunset platys, 2 Mickie Mouse, 1 Serpae Tetra
Yes, I've forgotten the exact name of all but there are Anubia, Sword, Val, Crypt, Hygrophilia diformis, Java Fern
Weekly, 25% to 30%
77deg F., ammonia - 0, Nitrite - 0, Nitrate >10<20

 

[avraptorhal]

oxygen content

By this time next week I'll be able to better answer some of the good questions you have asked. I've ordered a digital camera and expect delivery early next week. I absolutely appreciate the questions, they make think my questions thoroughly as I ask them. I'm learning, thankfully!!!!!

 

[Byron]

29 Gal

2 sunset platys, 2 Mickie Mouse, 1 Serpae Tetra
Yes, I've forgotten the exact name of all but there are Anubia, Sword, Val, Crypt, Hygrophilia diformis, Java Fern
Weekly, 25% to 30%
77deg F., ammonia - 0, Nitrite - 0, Nitrate >10<20

Nothing stands out here as a problem (re the water).

I don't know your level of experience, so I will just make some observations which may or may not be known already. Platy do like to stay near the surface, they feed from the surface so this is a natural behaviour as they would be searching for insects landing on the surface. With all the water movement from the old filter, it may have been too strenuous on them, but now they are more settled and will show more natural behaviours. Just a thought.

By the way, one Serpae Tetra is almost certainly going to cause you trouble. This is a shoaling fish, requiring a good sized group (8 is minimum, more is better), and it has a well-deserved reputation as a fin nipper. Such behaviours are usually intensified when the group is less than 8. Given the tank size, you could do a group of Serpae but this would basically limit any other fish to zero. Another option would be to return the lone Serpae and select a peaceful shoaling fish from among the tetra. Click the shaded name to read more about the species.

Byron.

 

[avraptorhal]

I'm a newbie. Started tank in August of last year.