Moldy Filter And Sickly Betta

[attibones]

My friend's betta has been looking rather bad lately. He's lethargic and doesn't move much off the floor. He's supposed to be a halfmoon and used to have rather lovely fins when we bought him a year ago. I cycled the tank fishless for my pal. He was doing really well. The tank has always had a bit of a diatom issue, but that's because my friend got special plant substrate and, like, three plants. She didn't want to get more than the three plants, even though I told her she would have an algae problem, but no one listens to me. 
 
A couple months after keeping the single betta in this ten gallon she decided she wanted to get some more fish to handle the algae issue. I told her the best way to handle the algae would be to reduce the photoperiod and change the substrate to regular gravel. But my buddy again didn't listen and then bought a couple (or was it three?) rubberlip plecos. She didn't know about isolating the fish so she introduced a horrible ich infestation as well as some kind of bad fungus. All the plecos died. The betta had ich but he also looked like he had columnaris or something. His fins got really short through all this. 
 
He's been looking rotten for a while now and never seemed to recover from the ich and whatever else. Today I checked on him and noticed that there was mold growing on the top of the floss in the filter. I tossed out the floss, but left the sponges in the filter. This filter does not appear to get the top section of the media wet. I guess there was just enough moisture and just enough warmth to foster a white mold. 
 
I'm not really sure what to do for the guy. I'll do a water change for him tonight (my friend is out of town for the week). Any ideas? I'll do some water tests in a minute and post results. Should I euthanize him?

 

[nic1]

oh no! At least he has you though......
sorry-I dont really have any betta experience so Im not going to 'try' and give any advice for him, but dont euthanize him without telling your friend first.
:s

 

[Meeresstille]

I'd rather turn the whole tank into a quarantine tank first before euthanizing the fish. He may still have a chance. Toss the filter (media) if you're afraid it has been too contaminated, and leave the tank unfiltered for now, changing the water daily. Try some Epsom salts if you think it may help. He's only 1 yr old!

 

[attibones]

I have tons of spare filters with cycled media in them in my tanks. As I'm going out of town today too (another friend will be watching the houses and our fish) I won't be able to do any daily water changes. The most I can do is one more today. Would swapping the filters out be at all beneficial? I can also add some of my extra floating plants if it would make a difference. I also have a sponge filter I can throw in.

I didn't see anymore mild last night when I was checking out the filter, but I'm assuming it can't be good for the betta. Could the mold be causing all his issues?

 

[Meeresstille]

It would at least give him a chance. I believe the mildew/mold can cause his issues. They would reduce the water quality, and poor water quality is often the culprit for fish getting sick.
 
It may even be worth it to clear out everything in his tank, and start the tank from scratch. If you have the time. I would even add a bit of aquarium salt (or kosher salt) to the tank. 
 
Is the tank sitting in a damp room? Maybe finding a different spot for the tank could help as well.

 

[attibones]

The room isn't very humid. His tank is in front of the fireplace which we boarded up because of bats (we did this before we got the fish). When she gets back from her vacation, I'll suggest to my friend that we clean out the tank, though I believe she'll say something along the lines of "well he's getting old so lets just let him live out the rest of his life." She really doesn't believe me when I say that one year is very brief for a betta. I've left town now, but our other friend may be more willing to help out. I'll ask him if he'll move one of my filters over and do another water change. 
 
At my house I have epsom salt, spare filters, spare heaters, spare tanks, plenty of extra plants, extra ceramic media (but I'm out of sponge), leftover sand (about thirty pounds) and gravel and possibly some other equipment. I'm coming back into town on Saturday or Sunday, my friend around the same time. If he's still alive by the time we both get back, I'll throw the idea of switching out the tank at her. 
 
I think she wants to do a community tank. She thinks that lyretail mollies would be swell. I told her they need bigger tanks and suggested other smaller fish. She said the LFS worker sounded knowledgeable and offered to test the water, so clearly I am just obsessing and don't know as much as I think I do. I reminded my friend that we have our own test kits (it was the second thing I made her purchase when we were setting up the cycle) and they are more accurate than the ones petsmart does. 

 

[attibones]

The poor fellow died.

I'll be helping my friend redo her tank this week. I'll give her some of my floating plants and one of my filters as well as some better suited substrate. I told her we had to totally clean the tank anyway. Maybe we will get her a lively community tank with some active guppies or something so that she won't feel the need to buy extra fish.

 

[Meeresstille]

So sorry about the Betta. The Guppies sound like a good idea. But they would all have to be males to not overload the 10 gallon with guppy-babies.

 

[attibones]

Of course we would only do males. My LFS occasionally gets some nice looking endler crosses. Maybe she'll want some of those instead of the much larger and completely inappropriate fish the staff suggest.