Help my fish are dying?

Question

Over the last few days my fish have started dying one by one. I had a problem with fungus which i cleared but now this! They seem to be going to the top of the tank and gasping for air,there is nothing physical on them to say they are ill. I did a water change last night to see if that would help but it hasnt. I have a 18 gallon freshwater tank which has been running since november. Any help would be appreciated

Answer 1

20% water change with gravel vac. Two days in a row then take a day off. You need to do this slowly. Some people will do a 50% water change, which more often than not will cause too many problems on its own. After about 3 water changes (should be enough) you need to get into the habit of 20% water changes every other week. This will greatly reduce illnesses in the future.

Answer 2

What is your ammonia level in the tank? Have you tested the water? What kind of filter are you using?

Water changes are good to keep ahead of this plus adds back much needed dissolved oxygen.

Dissolved oxygen does not enter your tank by means of air stones. Dissolved Oxygen (DO2) enters the water by movement of water against air, filters, powerheads, waterfalls, waves etc.

Try dropping the water level in your tank 1/2 - 1 inch. This will allow your filter to DUMP water into your tank like a waterfall creating much needed DO2.

Your filter should be large enough to over turn the water in the tank 3-5 times per hour. Your tank20 gallon needs a filter which will turn over 60 gallons per hour. Like a whisper 20 or a tetra 60.

Try dropping the water level for now. If your fish show signs of improvement, you are going to need a better or more powerfull filter.

Test your water. Ammonia is a silent killer in a tank

Good luck and if you need more info, feel free to email me

Answer 3

Are they receiving proper filtration and air? You need to see the water moving reasonable strongly when you move the pipe of the filter to point towards the surface.

If you don't have a proper filter, then get a underwater filter from an aquatic store, it's easy to install. Make sure it's the right size for your tank. A filter will move the water in your tank and this way create oxygen for your fishes.

Alternatively, get a pump which creates air bubbles.

From what you explain, your fish do not have enough oxygen.

Answer 4

Hello there,

When fish gasping on the surface it is usually due to low O2 content in the water. Did you put aeration to your tank?

Please be careful that some fish medications such as Formalin can lower dissolved O2 content in water. therefore they should be given with enough aeration.

When a fish died w/o external physical abnormalities and just in a short time (hours-days)... my guess is ammonia, chlorine, or other toxins in water. Not infection.

Hope that helps.

Answer 5

a big tank like yours needs a big air pump if you don't have one go and buy one also some plants and opening the tank's lid a bit so that outside air can contact the water surface will help your fishes to get more o2, also make sure that your tank isn't too hot since it will lose more o2 that way.

Answer 6

It sounds like your fish are suffocating from lack of oxygen. The tank needs more filtration, circulation, and/or agitation of the water. Please read all you can about setting up and maintaining a healthy aquarium at wetwebmedia.com or google "tropical fish care". Good luck.