my piranas..... a little help plz

All I can think of is maybe a fungus or water lice. Do you see any white spots that kinda look like salt or extra slime or anything like that on the fish?

I would recommend changing from goldfish flakes to tropical fish flakes there is a slight difference in ingredients and it will help make their colours brighter.
also maybe add some bloodworms or tubifex worms as a 1-2 a week treat.
just to change it up a bit. blood or tubifex are just treats and are your choice but definately change the flakes.

I would also recommend getting a bigger tank for that many fish. Or at least a powerful filter say for a 50gal. and a good airation stone/block.

Well, the Pygocentrus Natteri or ... Red Bellied Piranha Often found in the amazon waters of crap, like to poo. No sorry cant help, change your water, drink your water, love life...........

maybe someone who knows what they are talking about can post a reply... DUN DUN
DUN

The behaviour you're describing is called 'flashing', and fish often do this to try and rid themselves of parasites. If you see little white spots on your fish - almost like grains of sugar or salt - then you've probably got a case of ich in your tank. It's common, and frustrating, but not too hard to take care of in most cases.

There is loads of info here on AC about treating ich. In short here's what I would do (I use salt/heat because I don't like using meds in my tank; some people have great success with various medications).
- Turn the heater up (gradually) to ~86F - this shortens the parasites' life cycle, and I've seen it said that ich has a hard time surviving at all above 85F.
- Add salt (table, pickling, kosher, aquarium, doesn't matter) to the water. Dissolve it in water, and add 1tsp per gallon of water (in a 25g tank ~20g if you've got lots of decorations, ~22 or 23 otherwise - it's not crucial to get it exact, you can use more than 1tsp per gallon and not hurt your fish)
- Change 25% to 50% of the water daily, vacuuming the gravel. This removes many of the parasites, and gives the fish a clean environment to help them heal.

Ich lives in stages - free swimming, attaches to fish, falls off and multiplies while living on the substrate, then hatches to become free swimming again. You can only kill it with salt or medications during the free swimming stage. Continue the heat/salt treatment for a full week after you see the last spot fall off the last fish - this way you know you've gotten the last of the free swimmers (they will hatch a few days after falling off the fish, so if you discontinue treatment when you stop seeing spots, they'll reinfect the fish within a few days and you will have to start all over).

Best of luck. If it doesn't look like ich, let us know and if you post a detailed description of what's going on maybe someone can pinpoint the problem.

Most other parasites such as velvet will also be sensitive to salt and extreme heat. best of luck to you!

You have all those fishes in a 25gal? LOl!

I would try salt and increased heat as a remedy first. Do a search for salt and ich treatment on the forums. It is cheap and often affective, without introducing harsh chemcials to the system. You really should think about getting rid of many of those fish. And those pirrahas really need a much longer tank or will probably turn into really horrible pets as they freak out all the time.

25 gal
2 rock bass 1'
2 striped minnows 2-4'
3 shiners 4'
4 (2 1/2) (3') pirana
1 black crappie 1'
2 sunfish 1'
2 ghost shrimp left of 6
5 goldfish left of 12

Click to expand...

I just about fell outta my chair when I first looked at your tank - 2 foot long bass?? Whoa! Then I sat and thought about it, and I really really hope that's a typo. ' = feet, " = inches. Nonetheless you're gonna have BIG problems with your stocking levels soon enough. Anyway, thanks for the unintentional laugh.