fish at the surface

[spennylane]

Hi, have acquired a 16 gallon tank with 3 surviving fish - 1 x zebra danio and 2 x guppies I believe. The fish all seem happy enough, eating swimming etc - however they seem to spend about 90% of their time at the very top of the tank - as close as they can get to breaking the surface. I have been testing the water and the ammonia, nitrate, nitrate, phosphorus levels are all fine.... what do you think is up with the fish??? Would you suggest adding some more danios yet? or waiting? until what?

 

[Mr Miagi]

What kind of filtration and airation do you have?

 

[Inchworm]

Hi spennylane

I just responded to your first question, but I think this post sheds some more light on the matter. I would say that judging from the way your fish are behaving, they are starved for oxygen and are spending their time near the surface because the amount of oxygen in the water is greater there.

Water absorbs oxygen from the air through its surface. As the surface moves, the oxygen gets circulated throughout the tank. If this isn't happening, something is wrong and it can lead to major problems.

I would suggest you do a good water change to refresh the oxygen supply immediately. This will also eliminate some of the harmful bacteria that thrive in still water. Is your underwater filter run with an air pump? If so, it might be an easy matter to attach an airline with an airstone at the end to circulate the water.

Have you tested for Ammonia, Nitrites and Nitrates in the water? That should help us to determine how effectively your filter is working. If you are in doubt, do another water change.

If you decide that your underground filter is not working as it should, taking it apart will do little but postpone it from happening again. It would be better to replace it with a Hang on the Back style filter,

And, what happened to the other fish that had been in the tank?

 

[spennylane]

there is a large filter - built into the tank - this came with the tank and is working well - however it doesn't cause the surface water to break at all - have read on another thread that turning the nozzle upwards may solve this (it does seem quite deep under water though) There is no other aeration - the local pet shop said it wasn't needed other than for decoration.

 

[black angel]

sounds like a juwel. i have one of those and its the same size. to get the surface moving i turn the nozzle so its pointing upward but you can buy kits that for a couple of pound that attatch to the nozzle and so bring air down. how often are you doing water changes and do you use dechlorinator too?

 

[boom-sage]

yes, you should get a bubbler. try a rena 200 wit a rena micro bubbler 3 inch on it.

 

[spennylane]

thanks for all of your replies, I turned the nozzle round last night so it now disturbs the surface and the fish seem so much happier! All the levels are fine, I will do a partial water change tonight and look into one of those kits! Thank you so much - I can start to think about stocking it soon.... - don't know what happened to the other fish - my friend wasn't exactly an enthusiast - more a case of the strongest survive so I guess my three are pretty strong!!