Gourami has eye problem

[Kbwils01]

My opaline gourami is at least three years old and for the past 3-4 weeks they have been very lethargic, pale, and have clamped side fins. They also had a few tiny air bubbles on their scales (clear air bubbles, not ich spots). I increased the tank temp from 76 to 78, lowered the flow of the air stone, and increased the length of their night time light cycle. Today I noticed one of their pupils appears to be translucent? The lens is still there but the blackness of the pupil is gone. It's very strange and I've not seen anything like this. None of the other fish in the tank are experiencing symptoms. Following an ichx/melafix treatment the gourami does appear to be doing better, smoother scales, no air bubbles, a little more color, spending more time at the top of the tank, so they appear to be on the mend but I hadn't noticed the eye. Could this be a result of the ichx treatment?

Tank size: 30g
tank age: 3yrs
pH: 6.7
ammonia: 0
nitrite: 0
nitrate: 0
tank temp: 78°f


Volume and Frequency of water changes: 10 gallons (33%) changed weekly

Chemical Additives or Media in your tank: 1 activated charcoal filter in each marineland HOB filter (2 units). Each HOB unit has a spinning "bio-filter" as well.

Tank inhabitants: albino bristlenose pleco, Columbian spotted pleco, yoyo loach, five neon tetras, 3 endlers guppies, opaline gourami, 3 gold barbs

Recent additions to your tank (living or decoration): 3 endlers guppies in April

Exposure to chemicals: last week the tank received three daily doses of ichX 24 hrs apart after noticing the gourami had a pale mucus poop (treats ich, Velvet, Saproleniasis, Trichondiniasis, Fungal Infections, Protozoan Caused Diseases). 50% water changes between those treatments, with night time lights only to reduce stress, activated charcoal filters were replaced after the final treatment and subsequent water change. It has been a week since chemicals were added, today I added the usual aquarium salt and melafix (planning three day treatment of melafix).

Photo of bad eye:

Photo of normal eye on opposite side:

 

[Colin_T]

Is the eye red?
If yes, that would be blood and they eye has been damaged. If the damage is not too severe, the eye usually recovers after a few days to a week. If there is significant damage, the eye will be blind.

Did you remove the carbon from the filters when you used the medications?
Carbon will remove medication and plant fertiliser from the aquarium water.
If you had carbon in the filter while using medications, through the carbon away and replace it with a sponge.

You don't normally need carbon in filters unless you have heavy metals or chemicals in it. Then it's preferable to do a big water change with clean water to dilute the stuff in the water.

 

[Kbwils01]

Is the eye red?
If yes, that would be blood and they eye has been damaged. If the damage is not too severe, the eye usually recovers after a few days to a week. If there is significant damage, the eye will be blind.

Did you remove the carbon from the filters when you used the medications?
Carbon will remove medication and plant fertiliser from the aquarium water.
If you had carbon in the filter while using medications, through the carbon away and replace it with a sponge.

You don't normally need carbon in filters unless you have heavy metals or chemicals in it. Then it's preferable to do a big water change with clean water to dilute the stuff in the water.

No the eye isn't red - the red you see is inside of his head. Other than the one blind eye he is swimming at the top and looking well again.

Thank you for the info about filters - I didn't know that! I do take them out when I dose the tank but I thought you had to have activated charcoal for normal daily running. I'm planning on a trip to the store soon to get just a sponge filter.