What's wrong with my pleco?

[Seedy J]

I've got a 55 gallon tank that's cycling (no more ammonia, but nitrites are high) populated with 4 various gouramis and 2 plecos. Two of the gouramis got ich last week Tuesday, and I've been treating the tank with Ich-Attack ever since. The ich disappeared a few days ago and all seemed well, but yesterday I saw one of the plecos looking like this:



The big white spot by his mouth is new. According to the disease guide here, if it were ich it would be little white spots so... what's wrong with my pleco?

 

[Seedy J]

More info:


2. What are your water parameters? State the brand of test kit used.
As of yesterday, Ammonia: 0, Nitrite: ~5 ppm, Nitrate: close to 0, pH: 7 (as best I can tell)
API

3. Is your aquarium set up freshwater or brackish water?
freshwater

4. How long the aquarium has been set up?
Since May 16th

5. What fish do you have? How many are in your tank? How big are they? How long have you had them?
Opaline gourami, ~2 inches
Gold gourami, slightly smaller.
Above since May 16th.
2 common plecos, about 4", since May 24th,
Albino paradise fish and pearl gourami, a little over 2", since 5/26

6. Were the fish placed under quarantine period (minus the first batch from the point wherein the tank is ready to accommodate the inhabitants)?
No (no place to put them).

7. What temperature is the tank water currently?
79-82 F

8. Are there live plants in the aquarium?
Yes

9. What filter are you using? State brand, maintenance routine and power capacity.
Tetra Whisper EX70 (now without carbon for the Ich-Attack)

11. Does your aquarium receive natural sunlight at any given part of the day? What is your lighting schedule (assuming you do not rely on sunlight for our viewing pleasure)?
It's not in direct sunlight, but it gets sunlight. The lights are usually on from around 8 AM to 10 PM.

12. When did you perform your last water change and how much water was changed? How often do you change your water? Do you vacuum the substrate?
A little over a week ago, about 8 gallons, vacuumed substrate a little bit. Planning to do a 14 gallon water change tomorrow.

13. What foods do you provide your fish? What is the feeding schedule?
Tetra Color flakes, Ocean Nutrition algae wafers, given once at night.

14. What unusual signs have you observed in your fish?
No unusual behavior

15. Have you treated your fish ahead of diagnosis? If so, what treatments did you use? State your reasons for planning ahead of proper diagnosis.
Not for the problem the pleco is having.

 

[pinkertd]

I don't know exactly what the big white spot is on your pleco, but it's definitely not ich. Your may be in big trouble by adding more fish too soon before the cycle is complete. It is good that there is no ammonia, but nitrite can be just as deadly if not more so than ammonia. It will burn the plecos gills making it almost impossible or impossible for them to breathe. As long as you are showing nitrite, and .5 is high enough to kill, you need to be doing bigger, more frequent water changes until the nitrite is gone. At that point you should see the good nitrate going up. An 8 gallong water change a week or a 14 gallon water change a week in a cycling tank is not enough. You have 55 gallons with nitrite at .5...IF you changed 23 gallons of water out, your nitrite would drop in half to .25, and that is still not acceptable. I would do yet another 50% water change (23 gallons) to bring the nitrite down by half again to .12-.13ppm. Then measure the nitrite every morning and evening. When it rises, do a 50% water change to cut it in half. I had this happen in a 75G and it took just about a week of daily water changes to straighten out. I did loose fish. It was an unexpected nitrite surge in a new tank for the baby plecos. And everytime you do a water change, be sure to vacuum the gravel. Don't be afraid of vacuuming the dirt out. Plecos, especially common plecos create a ton of pleco poop which is going to show up right now as nitrite. And large water changes, aside from making your water more tolerable for the fish while the tank is still cycling, is also going to do wonders for any sores or cuts or ragged fins. You may see the big white spot get better. If it's at all possible, can you take a big close up of that spot?

 

[Seedy J]

Thanks for the advice, and sorry I was so slow to reply. The day after I posted, the nitrites disappeared and haven't been back since. On Thursday, I started using Mardel Maracyn Plus (sulfamethazine and trimethoprim), but it doesn't seem to be doing anything yet.

Now I'm having another problem - both plecos have swollen bellies and white stringy poop. From what I can find, this sounds like internal parasites and I need to get something with metronidazole to treat it. Does that sound right?

Edit: Oh, and here's a better pic of the white spot (the one I posted before was supposed to be a clickable thumbnail, don't know what happened there).

http://yfrog.com/5ddsc07174fj