Sick Mollies

[ManicPenguin]

I have 4 of my original 6 dalmation mollies. I got mollies because I read that they are hearty and a good starter fishand I haven't kept an aquarium for 15 years....start slow right?

Anyway, I have lost 2 of them and now the other 4 look sick.

The mollies are just sitting on the bottom..one is floating new the surface. They are super still and just hanging there. It looks like maybe 1 or 2 of them have a twitch to the side...like their tail is curling sideways involunarily....this is intermittent.

My water params are fine. Ammonia 0 Nitrite 0 Nitrate never above 10. I do 25% 2x/week wc.

I have 2 cories in the tank and 2 guppies. They are happy as clams, swimming about and eating.

The mollies are dalmations so it is hard to tell, but i am pretty sure they don't have ich. The 2 that died had no noticeable (to me) curvature of the spine or sores/red spots/flaking scales, rashes, etc.

Water temp is a little under 80*F.

I would salt the water a tad, but I think that would be really hard on the cories.

one of the 2 that died had an obvious swim bladder issue....he couldn't stay oriented properly. The other molly that died was a complete surprise. Now all 4 are acting lethargic and weird.

help.

Tank is 20 gallon with:
2 HOB filters
Heater
Aerator
Thermometer
Amazon Sword
Java Moss
Driftwood

 

[ManicPenguin]

I do have an unresolved issue with PH fluctuation. My tap is about 7.2-7.4 ish but it spikes over the course of a week to about 8...maybe a little higher. I have added driftwood and upped my WCs from 25% 1x/week to 25% 2x/week in an effort to stabilize the PH. I don't know what is causing such a high spike...It may be the substrate which is a mix I got with the tank used on craigs. looks like like it has bits of shell, crushed coral, pea gravel.

 

[ManicPenguin]

Also, I have VERY soft water....not sure if that matters. I use a water softener, however, it is a version that de-salts the water, so my salt content is virtually zero.

 

[AngelFishGirl]

If I were to guess, I'd say it's due to both pH fluctuations and too small of a tank. Really, for that many mollies, you should probably have a 40 gallon or larger. Preferably a 55 or so. They have a huge bioload and typically are supposed to be 30 gallons minimum for one.
For your tank, I would suggest guppies or platys?

 

[foster53]

Mollies do best in hard alkaline water, with salt added to it. The actually do very well in brackish water. Your soft water could be part of the issue. Are the mollies wagging, just staying in one place and swimming in place?

 

[ManicPenguin]

Would adding salt and hardening the water hurt the cories or guppies?

 

[foster53]

with cories you don't want to add salt. The guppies can tolerate a little harder water, as can the cories. If you do harden the water, do it gradually.

 

[ManicPenguin]

With a ph over 8, how would I harden the water without spiking ph ever further?

 

[pip walters]

Is the hardness still low once the pH reaches 8? What is the hardness of the tap water?

Water softeners remove minerals from the water. If your gravel contains shells (calcium carbonate) then this will dissolve in soft acid water and the pH and hardness should rise.

Mollies prefer hard water as mentioned by others. Try doing water changes using unsoftened tap water treated with dechlorinator and see if it changes. Your other fish should tolerate a rise in pH... in fact they already do, so using the tapwater as-is, may stabilise it somewhat.

 

[ManicPenguin]

The main reason I use the softened water is my well have a TON of iron in it. By ton I mean that if I were to fill an aquarium with well water, it would be orange in an hour.

The softener removes iron also so I can have clean water.

I have sand now in the aquarium....Quik-crete sand. I like it because it looks so natural and irregular. I may try adding crushed coral to the well in my HOB filter.

 

[ManicPenguin]

Well, all 4 mollies kicked off last night. :-( One looks emaciated, but she just gave birth so not a huge surprise considering they had stopped eating. No pinecone scales, but some red bloches...not sure if that was infection, or pigment since they had a bit of orange on them when i bought them.....though i guess I could have bought sick mollies. My guppies and cories are doing great...happy as clams.

MP