Fish Behavior... Fish Hanging Near Bottom Of Tank

[Theulli]

Hi

Never posted here before but I am at a loss.

Aquarium has been cycled for quite some time. 10G, a couple plates and a couple mollies, running the topfin 10G filter with some bio max added. Sits at 78 with little deviation.

I have consistently 0 ammonia, 0 nitrites, <5ppm nitrates. PH is a bit high at 7-8 but it has always been that way. Filter wise my aquarium does not seem stressed...the most recent Mollie didn't even cause an observable spike. Also have a moss ball in there.

So I have been concerned the last few days to see my fish almost all hanging out at the bottom of the tank, one even seems disoriented. I measured the water and did a water change and didn't think much of it (my theory was that the one fish Not sitting at the bottom, also the biggest and also the newest, is bullying, Dalmatian Mollie). But now one of them just died. No visible physical issues with the fish, no spikes in water measurements, but now there is the odd behaviour and a death....what should I be looking for?

 

[Pictusboss]

I’m not too sure. What I do know is that mollies get 4 inches and need 20 gallons. The plates are more than at home in a 10 gallon as long as there is 5 or less.

The only thing I could think of with the information you gave us is that if you have sand and not vacuumed it for awhile they could have stirred it up and got sick from the waste

I could also be internal, like bloat or terburculosis

 

[Theulli]

Thanks - I've got gravel, don't know if that rules out that theory.

I have heard mollies aren't suited for the 10 gallon tank (I have also learned not to listen to the phrase 'it should be ok' from certain fish vendors), could this all just be the one aggressive fish?

 

[Theulli]

Mystery solved. White spots all over one of the fish today so I guess we've got ick.