Fish At The Top Of The Tank!

[mjdennison]

Hi
My tank is about 6 months old it has a selection of fish including corys, clown loaches, plattys and a few others, it is only at about 50% of it's fish capacity.
Just the last couple of days all the fish are at the top of the tank! I have checked the water and apart from the nitrate bielg a little high everything looks OK. I did a 20% water change last night and all looked OK again but by this morning they are back at the top again
Can anyone throw any ideas forward on this

 

[helterskelter]

Are they gasping at the surface or acting lethargic, as this could be a sign of low oxygen.
However if you have power filtration or aeration from a pump this will help to resolve, if it is.

Are the fish acting strange, or do the gill look swallon at all?

 

[mjdennison]

Are they gasping at the surface or acting lethargic, as this could be a sign of low oxygen.
However if you have power filtration or aeration from a pump this will help to resolve, if it is.

Are the fish acting strange, or do the gill look swallon at all?

Hi thanks for the quick reply, I have a Ram and it's gills do look a little swollen but the rest look OK but they are a bit lethargic. the tank has a external filter but I do not have any extra aeration, having said this the tank has been fine for 6 months!

 

[Duck1976]

I had the same thing after my air pump packed in. Had to wait till the next pay day (almost a month) to get the next one and for the last couple of days the fish were spending most of their time at the surface.

Once that was in and up and running it only took a matter of hours for them to get back to normal.

 

[helterskelter]

Well their should be plenty of diffusion of oxygen, if the filtration is rippling the surface of the water.

Are they physical gasping though at the surface?

swallon gills could be a gill infection, have u added any new fish with in the last week or so?

I would do another 20% water change and then treat with melifix or myxazin. and see if that helps.

 

[mjdennison]

Well their should be plenty of diffusion of oxygen, if the filtration is rippling the surface of the water.

Are they physical gasping though at the surface?

swallon gills could be a gill infection, have u added any new fish with in the last week or so?

I would do another 20% water change and then treat with melifix or myxazin. and see if that helps.

I have not added any new fish for about a month, there is a reasonable amount of surface movement, I have some Myxazin so I will do another change and treat the tank, I will also put a pump on for a few days and see what happens. Again thank you all for your quick responce

 

[helterskelter]

Well keep us informed
Also have do u test your ammonia levels, this should be tested often as small levels can be a sign of problems before u see if in the fish.

 

[mjdennison]

Well keep us informed
Also have do u test your ammonia levels, this should be tested often as small levels can be a sign of problems before u see if in the fish.

Yep I have checked the ammonia and the nitrite levels and they are OK the nitrate level is a little up but it has been higher in the past with no adverse affects. I do a 20% water change about every 2 weeks as standard also the tank is well planted so this should help keep things stable. not sure what has caused this, I have struggled to keep the water temp up as the weather has been very cold but it's never dropped below 21c and if anything I think cold water holds more oxygen? I guess the next few days will be important.

 

[helterskelter]

Yes cold water holds more oxygen. Some temp change is is not a problem unless you keeping some rare fish. As long as it's done slowly.

 

[OldMan47]

At 21C you will likely find the platies a bit lethargic because their metabolism has slowed down. Depending on the type of cory, that can be too cold for them but many cories will do fine at that temperature. If your cories are hovering near the tank surface, there is something else going on and it may be a question that needs more exploring. Are you using CO2 for all the plants you have in the tank? If so what is the CO2 levels? Values over 30 are not considered safe for your fish.