Help- African Yellow Cichlid- Not Acting Right

[leann32]

Hoping someone can help me-please? Ok- I have a 110 gallon tank, 2 aqueon quiteflow 55/75 filters, heater, submersible UV sterilization light/pump and plenty of aeration. In my tank I have 2 blood parrots, 2 jeweled cichlids and 1 african yellow cichlid. I had 2 african yellows but about a month and a half ago tank ended up getting ick and the one died, despite treatment- everyone else did fine- tank has been fine since. So my problem is- I noticed my african yellow swimming erratically this afternoon, darting, swimming vertical, then this evening it did a death roll and then went into a little cave and was lying on it's side (I thought it was dead for sure then- but when I went to scoop him- though I'm not sure if male or female- he took off swimming and now is hanging out at the top of the tank underneath the filter and by the heater- and twicthing constantly- almost seizure like. There are no white spots, no velvet, nothing- just the erratic behavior. And he/she just came down from the bottom of the tank, spun in circles in a vertical position- went belly up- then corrected itself swam for a few seconds then sank to the bottom of the tank and laid on it's side for a couple of minutes before getting up and swimming to the top of the the tank. I just did a water change last week- my water parameters are normal and stable- pH 8.2 no ammonia, no nitrites or nitrates, temp 80-82 degrees. I put in the cichlid trace elements once a week, the lights are on a timer and they eat 2 times a day at the same time every day (autofeeder) so there has been NO drastic changes to the tank. The only thing I have done differently is added algaefix to treat a little bit of algae in the tank, but I followed the directions and the bottle said safe for plants and fish. All the fish entered the tank at the same time this past July, they all get along well. I really don't know what is wrong and I was planning on getting a new yellow next week to give him (or her) a buddy back- but now I'm not sure- and the reason I've waited in getting another one is because I wanted to make sure everything stayed stable with the tank. So- hoping someone can help me!! Thank you!!
Leann

 

[WILDER]

Need to ask you a far amount of questions to find out what going on.

It's rare to have a nitrate reading of 0. Do you have live plants in the tank?
What is your tap nitrate reading?
What the brand name of the test kit you are using?

Is the fish gasping, or signs of laboured breathing?
Does the fish flick and rub on objects in the tank?
Do the gills look pale with excess slime, red and inflamed?
Does the fish look bloated, or thin?
Has the fish darkened in colour, or gone pale?
What does it look like when your fish goes to the toilet?
Can the fish maintain balance in the water?
Check all your fish for a greyish film on body, fins
Any signs of red streaking, body and fins, red sores, red tiny pin pricks marks?
Is the fish still eating?
Does the fish swim in a jerky movement?