Mollie Bullying Gourami

[Phisher84]

I use to have 3 Dalmation Mollies in my 55 gallon tank, but due to temp. drops and lack of salt, I'm assuming, 2 of them croaked and now I just have 1. And he is a bully. I purchased a couple Opaline and Gold Gouramis last night and the Mollie went crazy over one of the Opalines as soon as I put him in the tank. All last night until I went to bed, he was chasing the Gourami and I think biting him. (Pursing his lips, looks like he's kissing?) He was at it again this morning as soon as I turned the lamp on. What am I going to do with this guy? I know he must be lonely, they should be kept in groups of 3 or more, but they're all just going to die again, so I'd rather not.

 

[KittyKat]

Temperature drops? What's going on there? These are tropical fish and your heater should have been keeping the temperature up to whatever you have it set at.

Mollies don't *have* to have salt.

Mollies are naturally aggressive. Even now I can see mine having a mini-war with a cichlid.

What are your water reading? Ammonia, nitrite, nitrate, pH, temperature.
How long has the tank been set up?
What is the filtration?

 

[Phisher84]

It was before I put the heater in, I did my first water change using a tap water purifier, but it was cold tap water. Only happened once, but everything else is stabilized now.

I put a tiny bit of salt in just when I noticed the Mollies being lethargic and I thought it would benefit the Betta as well. Also, one Mollie dissappeared for a day and when I finally got time to dig for him, I saw he was stuck in a piece of coral. I managed to get him out and save him, but he wouldn't swim after that, sat at the bottom of the tank all night, and the next day he was dead....by the coral. lol

My whole tank is semi-aggressive fish, so I expected a little bit of this, but until I got that Opaline, everyone left everyone else alone.

Tank set up for a little over a month, have a Penguin 330 top filter and a power head.

 

[KittyKat]

What type of salt? Some may be harmful to fish. Only aquarium salt and pure rock sea salt are considered to be safe at all times. Also there are a few species which do not tolerate salt at all (for future reference). Did you pre-mix the salt with some water before adding it? Putting salt directly into the tank may harm the fish, especially if they eat it.

Your filter is fine in terms of being able to deal with the bioload.. but only if it is cycled/matured. Is it?

If you do not have the tests to check your water quality, most fish shops will do it for you for free.