Mollies pestering betta?

[benjicanfreak]

I purchased a male betta (he is rather unattractive) and 2 mollies yesterday. I thought both of my mollies were male, but it turns out I have 1 male (dalmation molly) and 1 female (black molly). I am returning to the store today to get 3 more females.
My betta seems oddly terrified of my mollies, everytime they get close to him, he takes off in a fury, and he currently seems very stressed. I'm not quite sure how long I should wait for this behaviour to subside.
I haven't seen any fin nipping or anything from the mollies, they just seem very interested in him.
They are in a 30 gallon aquarium.
Also, my male is constantly chasing my female. Shouldn't this stop when she's pregnant? Which she obviously is.
Also, I can tell my female gets upset when my male constantly chases her, but when he stops and wanders off, she quickly swims to his side and bumps up against him and then he chases her again. Are they just playing?
I'm hoping that by adding the new females, this will help.
I don't think I'll need to quarentine the new females, since I only got my other fish yesterday, and they and the new fish (except the betta) will all have come from the same tank.
Also, my betta is spending 90% of his time at the top of the aquarium. He isn't very active, he usually just wanders slowly around the top. My tank is ay 78 degrees, and I added the required amount of aquarium salt.
Am I doing something wrong?

One more thing, the female mollies at the aquarium shop all have long, flowing tails and very pretty colours, will my betta think they are other male bettas and attack them? My black molly and my dalmation molly were the only ones without fancy tails and pretty colours, that's why I got them to put with my betta.

My tank is properly cycled and the water parameters are perfect.

This is my first time owning mollies, and I haven't had a betta in years.

Scratch the no fin niping. My male molly is practically eating my female. Chasing and biting, it's getting a bit out of contorl. They're leaving the betta alone though, and he sems to be up in spritis.

[platytudes]

Hello! Welcome to the forums.

My tank is properly cycled and the water parameters are perfect.

What are your water parameters exactly? If you don't have your own test kit, you should! Mollies and bettas like very different water conditions. Mollies need hard and alkaline water, and they do best in salty water. Bettas don't like salt and prefer water that's on the soft side. About the only thing they agree on is that they both like their water warm, 78 degrees is fine.

Mollies CAN be very nippy - the flowing tail of a male betta can be like a red flag in front of a bull. It certainly may subside when you get more female mollies, but it might not - in which case, you need a plan B. Either separate the male betta or see if you can exchange him for a female - they move faster because of their short tails.

Shouldn't this stop when she's pregnant?

Nope. Males pester females practically all the time. That's why you need more females than males - 1:3 male to female ratio at least - so that the pestering can be spread out.

Are they just playing?

Likely something related to mating. Always wise to have more females than males.

One more thing, the female mollies at the aquarium shop all have long, flowing tails and very pretty colours, will my betta think they are other male bettas and attack them?

It's possible. Bettas have different personalities - some are more feisty than others. There's really no way to know for sure, but as I said before, I would be ready with a plan B for the betta. They are easy enough to keep on their own in a 5 gallon tank, and great in 10 gallon tanks with other small fish or shrimps, such as cherry or ghost shrimp.

Am I doing something wrong?

Well, we don't really know much about what you're doing - just what fish you have and how they behave. You have a heater, that's good - what have you got for filtration? How long have you had the tank set up? What do you feed, and how often do you change water and service the filter? If you had that info, we could tell you for sure

Check your water at least twice a month, weekly if the tank is relatively new. You should have the same pH, alkalinity and hardness in your aquarium as you have in your tap, pretty much. Ammonia and nitrites should always be 0 ppm, and nitrate should not climb beyond 20 ppm. Mollies are sensitive to nitrate - they will start "shimmying" if nitrates get high or the pH and alkalinity starts dipping down. They also can be ich prone, so do keep an eye on them.

I wouldn't recommend keeping a betta in a community of mollies. For the reasons above (water chemistry incompatibilities) and also their diet is quite different. Bettas are carnivores who should be fed an occasional pea or bits of Spirulina flakes/pellets/wafers to keep from getting constipated. Mollies, like all the popular livebearers, should be fed a mostly vegetarian staple diet. A molly who eats a lot of meaty, protein rich foods will have intestinal problems, but these are the kinds of foods bettas need. Also, bettas shouldn't eat much - their stomachs are the size of their eye, and too much food will constipate them and give them bloat.

Bettas can be kept in communities, I have always kept mine this way. They do best with other small fish, such as rasboras and tetras, who like similar water chemistry, eat a similar diet - it just works out better to keep fish together who share the same needs. For example, mollies do much better with marine salt mix added to their water. Regular aquarium salt does nothing except add sodium chloride - marine salt (such as Instant Ocean or Red Sea) adds hardness and trace elements. Mollies are pretty much bulletproof in brackish tanks (tanks with marine salt mix added, but not enough to make full strength seawater) - but this is absolutely no way to keep bettas! Have you read this article about mollies, by the way?
http://www.wetwebmedia.com/FWSubWebIndex/mollies.htm

I hope that helps, take care

[Wetplants]

They are easy enough to keep on their own in a 5 gallon tank, and great in 10 gallon tanks with other small fish or shrimps, such as cherry or ghost shrimp.

Hmmm,... with shrimp? Sounds more like a snack than a tankmate. My 3-spot (related to a betta) loooooves live shrimp as a snack.

[Heidi]

I've never had bettas eat shrimp, just lucky I guess!

[sump'nfishy]

I've never had bettas bug shrimp either, the shrimp are always far too large. i think it'd be a good idea to separate the betta, mollies can be viscious.

[platytudes]

Hmmm,... with shrimp? Sounds more like a snack than a tankmate. My 3-spot (related to a betta) loooooves live shrimp as a snack.

I think it's doable with enough hiding places - ghost shrimp at least, tend to avoid getting wiped out, but there needs to be plenty of cover and rocky outcrops. I bet they would breed in my tank if I didn't have a blue female betta in there *sigh*

[Wetplants]

I was thinking that the babies would be more edible. An adult ghost would be quite a challenge.