Molly woes..

[Neon Jack]

Hello all i have a question. I have had my tank for about 3 weeks and i got 4 marble mollies today. They are in my 20 g tank with 3 platies, 1 pleco, 4 glowlight tetras and 1 pictus catfish. My tank has already cycled(ph is normal etc.) The other fish all are actively swimming around while all 4 of my mollies lay there at the bottom of the tank. Is this caused by stress or pregnancy? Any advice on this situation is a big help. Thanks!!! :)

[madagascariensis]

If aliens abducted a bunch of humans and dumped them into a strange and foreign planet, I doubt that they will be very comfortable. Same with new fish. Give them time and if they aren't up and about In a day, then investigate further.

[fishmommie]

Hi
I'm thinking that what you think is a cycled tank is not cycled at all. Sorry. If you just got your tank 3 weeks ago and you did not cycle it for approx 3 -4 weeks with no fish and using ammonia, then you do not have a cycled tank.
Consequently, you are now cycling with fish - which will take anywhere from 2 to 3 months with regular (sometimes daily) water changes. To have a cycled tank, your ammonia and nitrites must read 0 and your nitrates should read 20 or less. To cycle a tank with fish, you're going to have to test every morning before you change the water and if the ammonia and or nitrites approach .50, you need to do a water change.
please see the beginners section for the cycling stickies that explain it more fully

As for the mollies, it would be helpful to know what kind of dechlorinator you are using, what you have for filtration and what temp you're keeping the water. How often are you changing the water and how much?

Without knowing any more than what you told us, there are a couple possibilities. Stress for certain, could be the problem. If the PH in the water where you bought the fish differs from yours, they could be in shock.
If your ammonia and or nitrites are above .50 they could be suffering from ammonia poisoning. Check for ammonia and nitrites and, again, if above .50, do an immediate water change of at least 50%
You're pleco, BTW, is very much at risk in an uncycled tank as most toxins settle toward the bottom.

[MrsMolly]

Is it just me, or does the tank seem awfully crowded?