Bah!! What is going on?? **New problem and question**Pics

[Meredith]

I guess I just need to vent here. I would like to think I am careful and diligent in taking care of my fish. I do regular water changes, make sure they are getting proper nutrition all the while making sure not to over feed. I test the water regularly, and generally try to give them the best environment possible.
This morning I noticed one of my corys is missing his barbells, and the pleco may have a touch of finrot but I cant really tell. So I will be setting up the hospital tank today. And to top it off, The betta's tail (from a different thread) STILL is not getting better.
What am I doing wrong??? I am getting seriously discouraged here.

 

[Toirtis]

Diligent in gravel cleaning? Barbel erosion is usually caused by a minor wound becoming infected from bacterial nasties living in the gravel.

 

[Meredith]

I have sand in there with the cories. I think I do a pretty good job of getting the guck out when I do water changes. Maybe its time to pull out some of the decorations and clean underneath.

 

[greenmaji]

do you stir up the sand or do you use MTS?

 

[Meredith]

I just stir it by hand.

 

[BrianNY]

What's the temperature of your tank Meridith? Bacteria will reproduce rapidly at higher temps.

 

[Meredith]

I keep it at 79. The cories are doing well in their little hospital tank. Its so strange how empty the 55 looks without them in it.

 

[Meredith]

Well, I left the pleco in the 55, and now I see this was a mistake. She is mostly sucked on to the glass so I never really get a good look at her back, but tonight at feeding time, she came down to munch on her pea, and I noticed this white-ish patch of skin, and right in the middle it looks a bit like dandruff (I know its not ) I have two days worth of melafix in the hospital tank, but I would like to move the pleco over and start treating her as well. Is it safe to do this or should I wait until the corys are done with their meds then start over with Mrs. Hooper?
Also some pics of her patchy skin...





Also I just tested my water today, 0 ammo, 0 trites. between 5 and 10 nitrates, last water change was yesterday, about 40%.

 

[Toirtis]

I would wait. The white patch looks like it is probably just a minor abrasion from squeezing through a tight spot....I would not worry overmuch about it.

 

[Meredith]

Hmmm, she does like to hang out under the heater. I guess I will just keep an eye on it then.