black molly fish disease

Question
QUESTION: I am a beginner and I have had a 20 gallon tank for a little over three weeks now.  I have a red wag platy, a black molly, a yellow male guppy (that I no longer see in the tank)and a longfined red minor tetra.  The red wag platy has been in the tank for a little over 2 weeks and the tetra, guppy and molly for a little over a week.  The tetra and the platy seem to be fine but I have noticed changes in the molly's skin color.  Silver or what might be white spots are slowly covering his skin.  I am not sure if this is ick what should I do?  the molly is moving around and eating well I am not sure what this is.  Can you help? And will this affect the other fish.  And could the other fish have eaten the guppy (he didn't seem to be very healthy).  Thanks, Melissa

ANSWER: The other fish could have eaten the guppy or it could be dead under something or behind something. It could have died from stress, being bullied, or just old age. For the molly, does it look like white salt sprinkled all over the fish? If so, it is ick and the entire tank should be treated. Also, it is does look like salt, thus being ick, youu should raise your heater temp slowly to 80, not moving the temp more than 2 degrees every day. If you dont have an adjustable heater, just get the treatment for ick and treat the tank following the directions exactly on the bottle. If it does not look like salt let me know and I will consider it further. Let me know if you have any more questions.


---------- FOLLOW-UP ----------

QUESTION: Thanks for the response.  This does not look like salt sprinkled all over the fish and it does not cover the entire body just the gills, underneath the fish on the belly area and now it looks like it may be appearing around the mouth area and maybe on the fin.  It looks more like a dull color of silver or gray not very white.  The fish is also acting erratic and sometimes darting around the tank.  The temperature is about a steady 82 degrees and has been for sometime now should I adjust it.  also I have done regular maintenance on the tank about 25% once a week.  I have also had the water quality tested several times at my local pet store because I was concerned about the fish health but was told the water was fine.  Could this be stress because the tank is still fairly new or should I change some of the things I have been doing and not add anymore fish.

Answer
You should  definately wait to add more fish until the ones you have are healthy. I would also reduce your water changes. You should only change about 15% every two weeks. Every week gives unnecessary stress on the fish not to mention gives the tank a prone to algae booms. I think the problem sounds like t could be gill flukes or a externat parasite. Get a treatment which covers external parasites and treat it. It definately is something that needs to be treated so you should proceed with treatment. The temp should be fine as long as it is consistant. The higher temp is great to keep ick away, even if you fish doesnt have it now, it will prevent further instances. Often ick is the most common problem so the higher temp is very wise. Let me know how everything goes. As long as you have a good filter, heater and keep the tank maintained, it is pretty easy to keep the tank. You probably did not do anything to stress the fish but it just had it when you got it and it just developed into the problem by the stress of the transfer to your tank. Feel free to ask any more questions you may have.