Cant get ammonia levels stable

Hey I have a 110 gallon goldfish aquarium which was running great until a couple of weeks ago. My goldfish caught ick then had fin rot which I assume was from the high ammonia levels. I had 5 orandas die on me and only one survivor. The tank has been running almost 5 months prior to this. Filtration is a fluval fx5 stuffed with ceramics and polyfill along with the course filter pads. There is also a fluval 305 that has a coralife turbotwist uv connected to it. It is also stuffed with ceramics and poly. My ammonia tested 2.0 so I did a 50% water change and today its at 1.0. I don't think my tank was overstocked. They were not full grown probably around 4 inches in size. Any suggestions?

 

Welcome to Fishlore!

When the tank was running for 5 months, did you have the goldfish in there the whole 5 months?

Do you know about the nitrogen cycle? Was the tank cycled before you added the goldfish?

 

Ive cycled the tank for about 1 and a half months prior to putting fish in.

 

Just to clarify, not to sound demeaning but what do you mean by "cycled for 1.5 months" ?

 

Did you treat the ich with anything?

 

As in a added nitro bacteria to the water and waited until my parameters(ammonia, nitrite) were at 0 and stable for a period of time.

Fish were moved to 30 gallon qt and treated with ich medication, then melafix and aquarium salt for fin rot.

 

Ive kept both freshwater and saltwater aquariums for 10 years but never a goldfish tank.

 

When you added the bacteria, did you also add an ammonia source for those 1.5 months?

 

Yes sinking pellets

 

I wonder if those fish dying caused a spike, or if something happened to the cycle to spike the ammonia. How do you clean your canisters and media?

 

I have done nothing with the biomedia. Just replaced filter floss and cleaned course filter pads.

 

Once ich is noticeable in the tank its in the tank. The parasite may still be in the tank. I agree with texasdomer I think the fish dieing may of caused a spike in am.

 

The fish died in the qt tank which has stable parameters. One fish died in the main tank. I guess its a possibility.

 

I also raised the temp of the main tank to 88 when all the fish were in qt for about a week for the ich.

 

How often and how large are your water changes? What is your pH, nitrite and nitrates out of the tank? Can you also test everything out of your tap? What's the temp you keep them in usually?

 

When you moved the fish to qt did you keep cycle fed in dt? Might have crashed the cycle.... just spit ballin here.