Fish Dying Off, Help!

[Ghostknife89]

I currently have a 45 gallon tropical tank with aeration and a biowheel filter. The tank should be established, considering I set it up a year ago, and used water from my prior tank to set it up. I recently had a 4 year old ghostknife die, so I assumed it was old age. I bought a new ghostknife, as well as a shark cat. Both were dead a day later. Today, I just had an 8 month old angel die. The water has gotten cloudly, but I've been feeding the fish sparingly and have a new cartridge in the filter every few weeks. I do have an older Fluval 303 canister filter that I could use, but its so much of a hassle. The pH is fine, but the ammonia is high. What can I do to bring the ammonia down?

 

[CruX]

I currently have a 45 gallon tropical tank with aeration and a biowheel filter. The tank should be established, considering I set it up a year ago, and used water from my prior tank to set it up. I recently had a 4 year old ghostknife die, so I assumed it was old age. I bought a new ghostknife, as well as a shark cat. Both were dead a day later. Today, I just had an 8 month old angel die. The water has gotten cloudly, but I've been feeding the fish sparingly and have a new cartridge in the filter every few weeks. I do have an older Fluval 303 canister filter that I could use, but its so much of a hassle. The pH is fine, but the ammonia is high. What can I do to bring the ammonia down?

Water changes, big and fast. I am not familiar with your filter, where does the good bacteria build up in the filter, if it is in the cartridge you could be going back into a cycle every time you change the cartridge. You need to keep on top of the ammonia for a priority, and I might consider taking the fish back if you can't get on top of it. What fish are in the tank at the minute?

 

[Ghostknife89]

At this point, only four fish occupy the tank, a 4.5 year old pink gourami, a 6 month old pink gourami, an 8 month old angel, and an 10 month old iridescent shark. The cartridge filter has a wheel of filter material on it that is never supposed to be cleaned or changed. As the water passes over it, it turns. I believe that is what keeps the biological filter going. I do have gravel in the tank that I haven't cleaned in a while. Could this help?

 

[CruX]

At this point, only four fish occupy the tank, a 4.5 year old pink gourami, a 6 month old pink gourami, an 8 month old angel, and an 10 month old iridescent shark. The cartridge filter has a wheel of filter material on it that is never supposed to be cleaned or changed. As the water passes over it, it turns. I believe that is what keeps the biological filter going. I do have gravel in the tank that I haven't cleaned in a while. Could this help?

If the gravel is minging a good hoovering might be a good idea. Your priority now is getting the Ammonia and Nitrite down to zero. I would be interested to see what your nitrates are too, as it could indicate if the filter is going back into a cycle. One possibility is the addition of new fish was too much for the bacteria to cope with at once.

EDIT>

tank should be established, considering I set it up a year ago, and used water from my prior tank to set it up.

Just as a quick thought and point of interest, moving the water from the old tank will not have done much to help cycle it let alone mature it. Remember it is the filter you cycle not the tank. Saying that, with it being a year old it shoulf have been cycled.

How often do you change water and how much?

 

[Ghostknife89]

At this point, only four fish occupy the tank, a 4.5 year old pink gourami, a 6 month old pink gourami, an 8 month old angel, and an 10 month old iridescent shark. The cartridge filter has a wheel of filter material on it that is never supposed to be cleaned or changed. As the water passes over it, it turns. I believe that is what keeps the biological filter going. I do have gravel in the tank that I haven't cleaned in a while. Could this help?

If the gravel is minging a good hoovering might be a good idea. Your priority now is getting the Ammonia and Nitrite down to zero. I would be interested to see what your nitrates are too, as it could indicate if the filter is going back into a cycle. One possibility is the addition of new fish was too much for the bacteria to cope with at once.

EDIT>

tank should be established, considering I set it up a year ago, and used water from my prior tank to set it up.

Just as a quick thought and point of interest, moving the water from the old tank will not have done much to help cycle it let alone mature it. Remember it is the filter you cycle not the tank. Saying that, with it being a year old it shoulf have been cycled.

How often do you change water and how much?

I think that may be where my problem lies. I rarely change the water. What I generally do is let some evaporate and just replace it. I always assumed that as long as I had a good filter running, I wouldn't have to.

 

[CruX]

Ideally you should be changing 25% weekly.