sherri

I just set up a 55 gallon tank about a month ago--now my Tiger Barbs are getting very red streaks on their sides--I take it that it's a disease?? what do I treat it with--how do I avoid it next time??

click

Welcome to fishlore!

It says on your aquarium info that you do not know about the nitrogen cycle. If that is the case i suggest you read this link and buy a water test kit asap(drops recommended) and tell us your level of ammonia, nitrites and nitrates. You can also get your water tested for free at some local pet stores.

I suspect poisoning due to one of the three chemicals I just listed. You might need to do a partial water change as soon as you get those readings. An ideal tank will read ammonia 0, nitrites 0 and nitrates <20ppm. Any other concentrations above that will kill your fish in time.