white lump on my dwarf gourami

Question
Hi there. I have a 10 gallon tank with a hang on filter. I've had it for about a month and I'm pretty sure it's cycled. My ammonia readings are finally at 0 and have been for a few days now. ph is 7.8, nitrate 10, temp is between 79 and 80 depending how long the lights have been on. I don't have a nitrite tester yet. I have 1 gourami, 2 fancy guppies, 5 neons, 2 albino corys, and 2 baby angelfish. I know I'm overstocked and the angels will have to moved to a bigger tank but I didn't know that at the time if purchase.
So, my problem is....the dwarf gourami has a small slightly raised white bump on his side and also his long feelers are about half the size from when I first got him. What could the bump be and should I treat somehow. Will his little fins grow back? I tried to take a photo but he's very shy and hides when he sees me. Thanks in advance for you help.  :)

Answer
Hi Lori,

Testing for nitrites is going to be extremely important right now, especially if you just got rid of your ammonia.  Typically in the cycling process you have an ammonia spike and flat and then a nitrite spike and flat.  If you just saw the ammonia flatten it's possible you have nitrites and these are still 50% as toxic as ammonia and will leave your fish stressed and open to disease as well.

Do you have a heater?  I ask because I notice you said temp between 79 & 80 with the light so I'm hoping this isn't what you are using to heat the tank with.  It's very important that tropical fish have a constant, stable temp of 78 F so if you do not have a heater you will need to purchase one asap to keep the temp from plummeting at night or when the light is off.

The dwarf probably has an infection from the prolonged stress and exposure to ammonia and nitrites and the swinging temp.  It may be difficult to treat him with nitrites present and with the other fish that seem fine.  You will need to separate him into his own tank.  This can be as simple as a clear plastic rubbermaid container of no less than 10 gallon with a cheapy hang on filter and small heater.  This will be inexpensive and good to have in hand in the future anyway as a quarantine set up or sick tank.  You will need to use some water from the main tank (provided it doesn't have nitrites because they should be 0) some gravel and some plants to make it feel more like home and to avoid the sick tank from going through the cycling process with an already sick fish.  You can also add some filter sponge or media from your main filter to jumpstart it as well.

It's hard to tell at this point if your gourami has a parasite or a bacterial infection.  A white bump only doesn't tell me a whole lot about what is actually wrong with him.  This could be the start of ich, velvet, fungus or pox.  Some of those are bacterial, some are parasitic.  It depends on if the bump is small, making clusters, looks like baby powder, if the fish is darting about or lethargic, breathing heavily, laying on the floor, staying at the surface, if the white patch looks hairy.  More information would be helpful to accurately diagnose him.  

If the white is furry or hairy I would try MarOxy, for fish fungus.  However if the white is leaving trailing strings this is bacterial and I would try some Mardel and Mardel II.  These are broad spectrum anti-bacterial anti-biotics and will cure a range of issues.  Hold off on feeding 2-3 days.  Change out 25% of the water daily while medicating.  If you see no improvement after 4-5 days or you see he's getting worse or has other symptoms it may be parasitic and a new course of action will have to be considered.

Good luck : ) April M.