Redness At Base Of Pectoral Fins

[Rick A]

Hi,

Background:
I have recently moved my Malawis to a new bigger home. This was just over a month ago and the new tank was cycled (I kept about 100 Liters of their old tank water and used the original two external cannister filters - I alternate cleaning them, cleaning one of them about every four to five weeks) and everything in general has been fine - fish seem a lot happier and the fighting / harasment has subsided considerably.

Issue:
However, sometimes I hate that word, three of the bigger guys have appeared a little sluggish and I have noticed that they have some redness at the base of their pectoral fines and the area looks a little swollen. They are feeding and are 'pooing' as well. They still harass each other a bit and are not hiding or lounging around on the bottom... Over the past three days I have done daily 20% water changes and have dosed the tank with Melafix and things don't 'appear' to be getting any worse.

I have been keeping Malawis for nearly four years now, without any major issues.

Tank size: 330 Liters
pH: 7.8
ammonia:
nitrite:
nitrate:
kH: 13
gH: 11
tank temp: 76

Fish Symptoms (include full description including lesion, color, location, fish behavior): Three of the fish have redness at the base of their Pectoral fins and it looks a little swollen. They are eating, though not over enthusiastic.

Volume and Frequency of water changes: 330 Litres - I do a 25% water change once a week.

Chemical Additives or Media in your tank: Malawi salts and add Stress Coat water conditioner at each water change.

Tank inhabitants: Twenty various Malawis, most are about 3" with about six that are about 5.5"

Recent additions to your tank (living or decoration): Changed the substrate from gravel / crushed coral mix to coral sand and added about 35kg of ocean rock.

I'm not panacking yet, but I feel for these guys / girls and am a little worried that the others might start to show similar signs...

Question: Could changing the water so frequently at the moment be upsetting the balance for the bacteria / fish?


Thanks in advance

 

[drufly]

Never kept malawis but i dont see nitrite, nitrate or ammonia readings. People who do know will prob need them

 

[Rick A]

Nitrates, nitrites and amonia are almost zero. Some of the fish - literally two or three of them - were 'striking' for a couple of days when I first introduced them, but that has since stopped.

 

[drufly]

Nitrates, nitrites and amonia are almost zero. Some of the fish - literally two or three of them - were 'striking' for a couple of days when I first introduced them, but that has since stopped.

Nearly zero wont be enough as little ammonia is dangerous as is nitrite, nitrate is not as much a worry unless it is over 40. The mor info you can give the better it will be for people to diagnoss problems.

As for the stricking they would do this,i think, as they were only new to the setup.

 

[Rick A]

An update...

Well, after the stress that the last few days has caused me - and they say its the fish that suffer most from stress! - it looks as though the water changes are taking effect. The redness and swelling having almost disappeared in all affected fish.

However, it might be helpful to myself and others if someone with an understanding of this problem could pitch in, as I've seen a few queries on the Web relating to this problem, but no significant answers.

After joining a few forums lately, I'd have to say that this would definitely appear to be one of the better ones - knowledgeable people who regularly pitch in with advice and a friendly feel to it.