Listless Fish (update)

Question
QUESTION: Hi Dave! Im no novice, but this has me stumped: my fish have become more and more inactive to the point they barely move at all. I have a 55gal, 6 months into setup, containing a 3" golden gourami a blue catfish, an upside down catfish, and mollies. Several live plants. 0 Nitrites, nitrates between some and 20ppm, at 82-84 degrees. Im good about water changes...about 25% every 5 days or week. The problem is, each fish has found a little spot and just sits there. They dont swim around, and dont seem to be eating with nearly the vigor I remember. They dont seem to be in distress, more like...disinterested. Could they be just lonely, do you think? Or is there something wrong that Im not noticing? The upside down guy just hangs against the wall on the bottom and NEVER moves, that Ive seen, for at least a week. I have a QT with 6 more mollies and a pleco that are ready to go in, but Im afraid to add them if something is wrong. But if they're just lonely maybe more fish will help? :) Thanks for sharing your expertise with me to figure out whats going on. Cheers,
~Mia

ANSWER: Hi Mia:  This is just a random conversation that I am having with you... This is how I riddle out solutions to complex problems like yours...but read it carefully... there are important questions within...   when you change your water do you clean the gravel? clean under the decorations?  How much oxygen do you add to the water because warmer water holds less oxygen... Do the gourami's try to breath the surface air?  What kind of filter do you use? have you changed the filter media recently?   When I read your note the word fear comes to my mind as a possible reason... but what would the fish fear... there are  no predators in your tank... the catfish is acting normal.  What do you feed your fish... I try to feed mine a varied diet.  I have fourteen tanks and close to 80 fish...not counting fry... and when I come to any of the tanks with food I give the top a little knock and the fish come to the surface to see what I have...even the moray eel likes to see what I have...and she is grouchy.... Food is important to fish... The other thing you have not mentioned is the pH of the tank?  can you test the pH of the QT tank and the 55gallon and see if there is a difference?  If you have only one gourami... he is probably really nervous... they are shoaling fish and they need company.  I have a pair of gold gouramis that I have not had more then a week... they are still hiding behind the filter and are just barely social at all.  Gourami's like to feel safe or they hide... The upside down cat and the spotted cat may be more active at night and thus may be acting normal for their species... Molly's are one of the few fish I do not keep.. I do keep guppies which I admire a lot...Molly's seem to be smarter then the average fish but go out of their way not to show it... and just when you think you understand them...they change course... How many Molly's do you have?  are they just sitting there?  how large are they?  Molly's can be very aggressive and a shy gourami will cower from them.  I'm going to mull this over a bit longer... but if you can get back to me with the answers to these questions I can rule out some other possibilities... I would definitely consider getting a few more gouramis though... they do need their own kind... look too at the cats and see if they are more active when you shut the lights out... It is very possible that the blue spotted cat is hunting the other fish at night... this would cause the "fear"  that I spoke of earlier.  keep me posted... dave

---------- FOLLOW-UP ----------

QUESTION: Thank you for your quick response, Dave. I will try to supply the requested info...:
I do use a vacuum, and remove everything but the (6)live plants. I have one 55g rated filter (AquaTech, with activated charcoal) and a 5" airstone. I leave about an inch at the top for some extra "splash". I changed the filter  about a week ago, 2 days after vacuum and water change. The gourami surfaces and blows a bubble occasionally, but is not gasping. Ph is about 7.2. (registering "neutral" on the strips I have. The water reads as slightly hard.) The gourami used to have a "friend"...a spotted cat, who he "hung out" with all the time...the cat died during a bout of ick I went through about 2 months ago (treated with 86 degree water for 14 days, and a little sea salt; after, appropriate larger water changes) I have 2 golden mollies (one I just added from the QT tank last night as a test)...the gourami seemed to get along with the original molly (about 2"), and I thought because they were the same color they might have thought they were the "same". (My anthropomorphism of fish psychology is a little strange, I know, but I feel like Im not far off.) The 2 mollies just hang out at the top behind the heater now. The second (1") one was active in the QT tank with the others, now he's just as stationary as everyone else in the 55. I feel terrible I cant figure this out, you know? (And to make things worse, when I got home from work tonight and a dalmatian molly in QT was just...dead. Fine these last 13 days, in a tank that is supporting 6 (remaining) healthy fry!) ...So, say the Blue cat is a bully, and thats the problem (which I suspect, now that you've mentioned it)...what do I do with him? Remove him from the tank, or balance the tank's social dynamic with a larger, more balanced population? Or, on the other hand, do you think this is some environmental imbalance, disease, or whatever?
Respectfully awaiting your response,
~Mia

ANSWER: Hi Mia: I still feel this is a fear issue... and I still suspect the catfish as the aggressor.  fish react to each other and if one is afraid that radiates through the tank because the other fish want to know what they should be afraid of... but the reality is that they come from a world where they are as much the prey as the predator...so this is their instinct to be sill and unseen.... This is exactly why the new fish are being still... one they know nothing about this new environment unlike the QT tank.... I would call the local pet store... and see if they will take him for store credit which you can use to replace some of your lost fish... dave

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QUESTION: Hi, just thought Id update you. Im pretty sure the Gourami has dropsy, and as its been going on for at least 2 weeks now, that it (bacteria) has spread to the catfish as well, because his fins are ragged and he now has popeye. (I didnt have the heart to get rid of him.)Anyway, I put them both in QT and am using Maracyn-2 to treat. Today is day 1. The gourami is already swimming around more and they are even "hanging out" together at the bottom, like him and the other cat used to do. :-) Im considering dosing the main tank...just in case...but have not done so. (Thoughts?)  Just sticking to more frequent water changes for now. Ill let you know how it turns out. (BTW, do you have any suggestions for an easy way to change water, rather than lugging buckets? Some hose system, perhaps?)
Cheers,
~Mia

Answer
Hi Mia:  dropsy is not normally contagious... but they may have internal parasites... which would spread.  The gravel vacuums come in 25 foot hose lengths... though I just lug buckets... I have a system that fills up a bucket while I am draining a tank... just fill them half full and see if that helps..... I would wait on dosing the main tank to see if this med...which by the way is a good med... helps... dave