oxygen?

Question
My fish are all gasping for air at top of tank.  I do not know what size takn i have in water volume, it is approx 30 inches long and is approx 11 inches wide although the front of the tank is not flat, it is rounded. It is about 14 inches deep.  I have 4 bumblebee gobies, 10 penguins, 2 gourmais,5 black widdows, 5 cardinals, 1 sucker catfish, and 2 angel fish.

I think they are distressed, as they are almost all going to the top for air. this has been happening for approx 2 days now.

The gourmais are a new addition, and i do not know what their behaviour should be like, but they seem to be futtering around a lot, they almost look like they are trying to get out of the front of the tank.

I have very little knowledge of tropical fish, and am fairly new to keeping them.  We have had our set up for about 3 months.  We have only lost one fish, this was a black angel fish a month ago.  He was being picked on by a larger angel fish which we took back to the shop in the end as he was going after everything, and distressing lots of the other fish.

In addition the penguins seem to be hovering up the top all the time, and look like they are trying to breathe.

Its making me upset. i don't want to lose any or all of my fish.

I'm wondering if i should get a second pump?
or oxygenating tablets?

Going to clean it all out today, and do a half water change.


The water colour is ok, and the are fed frozen bloodworms each morning, a little flake fod in the evening.
I do not feed them on Mondays as advised by my pet store, to help keep the tank clean.

Please help!

Answer
Check your tank temprature, if it is to hot they are not getting enough oxygen, you can add ice cubes to slowly cool the water which help with adding some oxygen with the cooler temps.
Have your water tested, something could be going on chemically that you can not see that may need to be addressed. The half water will help if there is  a chemical issue along with temprature. Most tropical fish do very well around 78 degrees F. Adding a second air source may also be beneficial.
I hope you are successful with keeping your fish...Happy fish keeping!!!