white filmy areas on red velet swordtail

Question
Hi Chris,
I'm a little concerned about my female red swordtail.  First, here's the background info you requested.  I have a 30 gallon tank newly set up within the last couple months that has an aqua clear power filter.  It has 2 balas (getting bigger tank soon), 2 bosemani rainbow, 2 dwarf gourami, 3 danios, 1 neon, and the swordtail.  I did just recently have nitrite problems.  The color was way off the charts.  For the last week and a day I have changed the water daily, varying  from 20 to 25% each time.  I didn't add any salt or anything else as the advice I researched on the net varied and the only consistent thing mentioned were water changes and gravel cleaning so that's all I did.  Within the last couple days my nitrite reading is back at zero where it should be.  I have noticed on the red velvet swordtail areas where her coloring is lighter than the rest of her.  I guess I would describe it as filmy, white like areas but not really WHITE, just lighter than other areas.  It seems to be mainly from the middle of her body to the back.  I don't think it's itch because from what I've read that looks more like actual white spots resembling salt grains and my fish doesn't look like that.  She's still very active, eats, swims, doesn't rub herself up on anything, but still I'm concerned it may be something and I definitely don't want it spreading to the other fish.  What do you think this is and what should I do?  THANKS for your advice!!!

Answer
Hi Sherri;

It could be a reaction to the elevated nitrites but it could be a bacterial infection so watch to be sure it doesn't get worse. Columnaris is a bacterium that makes areas of the fish look greyish or whitish and then gets kind of fuzzy-looking. Here is a web page about it to see if that could be the problem;

http://tinyurl.com/35wh59

If that isn't it, she may be getting picked on by other fish. Observe them from a distance to see what's going on in there, especially during feeding time. If they see you they may not relax and act "normal". I hope she does okay...

At Your Service;
Chris Robbins