naomi_l5

Hi,

Can anyone help me, i have just bought 75l tank, had it a few weeks now and have 4 ( 2 black, 2 silver - don't which are male and female!!!) mollies in and 2 honey gourmani, one of my silver mollies is quite aggressive and chases the 2 other black mollies around, when i take the silver aggressive one out the 2 black ones are fine and start showing all their fins which hasn't happened before, just wondering if anyone knows why they would do this

Any help would be really appreciated !

Thanks*

newbie101

um how many gallons is 75 liters?? heheh...and is the tank cycled?
to help you sex your mollys, males have a tube-shaped anal fin, and females have a normal one. The anal fin is the fin on the bottom closest to the tail.

newbie101

oh nm about the gallons/liters thing I used the calculator on fishlore and its about 20 gallons correct?

naomi_l5

I think shes a female ( the one chasing the 2 black ones around ) she seams very aggressive to wards the others. My 2 black mollies seam to hide alot and have closed fins. *she doesn't attack any other fish? and doesn't seam to be bothered about the other silver one who is generally bigger and has a massive tail an long fins under its body.

are my other black mollies scared or are they ill. I did change about 25% of the water the other day hoping this might of solved the problem.......... BUT NO. * She stills chases the other black mollies around.

Just before i removed the silver Mollie (the aggressive one) to see if the other black mollies were any better without her around. * The 2 black mollies started swimming more freely and showing there fins. *i only removed her for about 5 Min's but once i put her back in the tank she started chasing them again like nothing had happend.

what should i do now.... PLEASE HELP

naomi_l5

I think its about 16.66 gallons. I'v just had the calculator out 2.

I belive 1 gallon = about 4.5 Litres

so 75L / 4.5G = 16.6666

Thats has close has i can get lol.

newbie101

try the caluclator on fishlore.com, that should be a bit more accurate. So is the tank cycled? Do you treat the water before adding it?

EmpPleco

Estimated you have 20 gallon it comes out to like 19.8

newbie101

yep, thats what I found, I guess its not 4.5 L per Gal?? I'll stick with the auto-changers lol...

naomi_l5

even better i have a 20G tank. What do you mean is it cycled? do you mean a filter etc.

Yeah i have a filter, heater and the temperature reads 26c. Yeah the water is treated and warmed before i introduce it back into the tank. I change about 18litres (25%) a week and feed them twice aday.

newbie101

cycled--could you read the article (on fishlore) on the NItrogen Cycle? This will help you a lot. I'm guessing your tank isn't cycled then.

newbie101

http://www.fishlore.com/NitrogenCycle.htm
Here, it might be a little boring but...

woodsplace1

seems like you might be changing your water too much? Read that article great one! You should only be changing the water once a month! She might be aggresive because of all the water changes. They recommended to me having 2 females and 1 male because of the dominance. If you do have 2 males and one female, just try and get 2 more females and see how she acts, cut your changing the water down to once every month and do a 50 % water change...hope this helps! Good luck! She might just be aggressive because the males will gang up on her at some time and she is trying to show them who is boss! You go girl!

vin

Once a month may be too infrequent. More like once a week would seem to be the norm and only about 20%-25% to keep things in check. However, if their tank hasn't cycled, daily water changes would be recommended until the cycle completes itself. Warmer weather is approaching as well, which also means time to spawn.......Sometimes, spring fever kicks in and nature takes over. Not entirely unheard of......or out of the realm of possibilities.

naomi_l5

thanks for all ur help, just have one more little question.....

recently most of my mollies have started sticking out these little fins - 2 sets of them one at the top end of their body and the ones under neath a bit further down their body out loads, does any one know whey they are doing this

thanks again !!!

0morrokh

Um...woodsplace 1, I don't know where you heard that, but once a month is not enough. You need to do 20 or 25 % water changes once a week in order to maintain good water quality. Weekly changes will not stress your fish provided the water is the same as in the tank, but poor water quality due to lack of changes will.
naomi_5, what fins are you talking about?? Look at an anatomy chart in a fish book to see what they are.

vin

Fish will extend their fins when they are feeling good. They have anal fins that extend when they swim or sometimes to help hold them stationary.

Dorsal fins standing tall is a good sign of a healthy fish.

EmpPleco

Not for all fish -- for some it means stressed/scared

I'm not sure if you were talking specifically for a molly or not

vin

I was talking in general.....Stressed and unhealthy fish are usually noted with sagging dorsal fins or clamped fins along with faded coloring....Typically fish with fins standing fairly tall and spread, are signs of health, alert and sometimes confrontational or in defense. They'll sometimes spread their fins to show their size as if to say 'See how big I am? Now stay away....'

I see it all the time with game fish.