Need a quick answer please, fish being strange

[3Corsameal]

right i just have convicts now in my tank, they are only 1 inch long, have been testing the water and it seems fine, no ammonia or nitrite, and a small amount of nitrate.

the fish are swimming near the gravel and then they kinda flick themselves off the gravel brushing their sides against it, like they are scratching their sides.

they aren't doing it constantly (they have a little outburst then stop) and its not all the fish that do it, also i can't see any marks or signs of disease on the fish???

don't think the water should be changed, because i've been advised by LFS that i should let it establish.

still have not one bit of algae yet, and tank has been setup since beginning of September..

 

[BrianNY]

Who knows why fish behave the way they do? You're tank sounds like it's perfectly cycled. What's the water temp? It should be around 78. Also, I hope you're doing partial water changes on a regular basis.

 

[3Corsameal]

water temp is set at 24 C

have been changing about 20% a week

 

[Fruitbat]

3Corsameal...

Keep your eyes open for Ich...you should be able to recognize it as tiny white spots that appear on the fins and then the body of your fish. Sounds like what you're seeing is what is sometimes called 'flashing'. The fish is trying to rid itself of something that is making it itch.

There are other parasites that can cause the 'flashing' behavior like 'anchor worms' and flukes but personally I'd be on the lookout for Ich. An overabundance of other microorganisms can also cause 'flashing' and so can, in some cases, a problem with water quality.

 

[William]

Also keep your eyes out for any whote fungal/white discolouration around their mouth and eyes.

Fish like to flash when they have something causing irritation, Ich, Anchorworms, Columnaris and anything that irritates the skin.

 

[Sati]

Have you never changed any of the water since Sept?

 

[basenjib123]

Flashing

Sometimes fish will flash off gravel, etc. in order to stir up some grub to eat. My Tinfoils do this all the time. Just some food for thought, Joe.

 

[Sinuhe]

It also seems to depend on the type of fish how likely they are to flash. My 2 Zebra Danios do it occasionally whichever tank they are in, but have never showed any other signs of disease, the water parameters are fine, and the other fish do it very rarely, or not at all. It has driven me crazy sometimes trying to figure out what's causing it, but so far I'm clueless. There's never been any sign of Ich in any of my tanks. The only fish illness I've had so far is some fin rot on my livebearers and Otos, but I've seen them flashing. Unless your fish are doing it constantly, I wouldn't be too worried about it, if no other signs of disease turn up, and the water tests show ok values.