Male Molly Chasing Guppys...whyyyyyyy?!

[LorLor]

Hello im new to this forum and have been reading lots of the posts, and am finding it really useful.

Ive had my tank for a few months now and after a very bad start its finally settled. (i started with 2 spotted mollys, 6 guppys, 2 gourmais and a leopard plec) unfortunately my water levels werent right killing many of them and im now left with a spotted molly and 3 guppys... im now waiting a while before i introduce anymore fish as the guilt was awful (i am a huge lover of animals)

Recently ive been gettin really annoyed because my spotted molly just spends alllllll day chasing my poor guppys, i woke this morning to find a guppy dead at the bottom of my tank and im not sure whether they're getting stressed with the bullying molly and this was the reason for the death?

any suggestions as to why my molly is being such an evil git?

thanks

 

[nmonks]

Male mollies are aggressive towards each other and tend to harass the females. Keep at least two females per male. Since they're all Poecilia species, mollies view guppies in much the same way as other mollies. Given their size and aggression, I don't recommend mollies be kept in tanks less than 30 gallons in size. The fact they are invariably easier to keep in slightly brackish water, choose tankmates accordingly.

Cheers, Neale

 

[LorLor]

Okay thankyou very much...however please may i ask you a little bit of advice?
None of the pet stores round here seem to know what they're talking about really...
My 3 guppies are female and my molly is male. If i were to get anymore fish what would you suggest? And is it neccasary that i use Aqualibrium salts? One store told me that i should be using it but is this just a ploy to make me spend more money? I'd appreciate any advice that you could give me, as its clear that you seem to know what you're talking about thankyou

 

[nmonks]

Thanks for the kind words!

If you have three female guppies in with one male molly, it isn't at all surprising he's chasing them. How big is this tank? If it's small, there's very little you can do to stop the fish "bumping" into each other.

Do you have any floating plants? I strongly recommend you get some floating Indian fern. You don't need much (if you're anywhere near Berkhamsted I'd be happy to donate a clump). Once introduced, it grows quickly. The good thing is that it provides shade and cover, and you'll find that if the females can hide, they'll be harassed somewhat less.

The addition of a little salt is beneficial. I'd recommend marine salt mix rather than anything else. A box of marine salt mix costs about £5 for 1.2 kg box. You only need to add 3-6 grammes per litre, so a box will last a long time. The thing with marine salt mix is that it raises pH and carbonate hardness, not just salinity. Yes, this does help; mollies in particular are sensitive to low pH levels and apparently high levels of nitrate, and the carbonate hardness inhibits the first issue, while sodium chloride detoxifies the nitrate, reducing the second problem significantly.

There are endless arguments about whether salt is *strictly* necessary, but for most casual fishkeepers, keeping mollies in slightly brackish water will indeed make them easier to keep. Both mollies and guppies thrive in slightly brackish water, and both like somewhat warmer than normal water too, around 26-28 C, so they're a good combination in that regard.

There are many things that are sold primarily for making money. Non-aquatic plants for example, and freeze-dried foods, and activated carbon. None of these things are terribly helpful and may, under some circumstances, cause problems. Non-aquatic plants die, freeze-dried foods* promote constipation and bloating, and carbon removes medications. So I certainly wouldn't recommend stuff you don't need!

Cheers, Neale

*Flake is fine, but augmented with some live, green, or wet-frozen foods helps. In the case of mollies and guppies, algae-based flake is what you want. The stuff to avoid is, for example, dried daphnia and dried bloodworms. These are massively overpriced for what you get, and they do indeed seem to cause digestive tract blockages if used excessively. Imagine if humans just at beef jerky all the time!

Okay thankyou very much...however please may i ask you a little bit of advice?
None of the pet stores round here seem to know what they're talking about really...
My 3 guppies are female and my molly is male. If i were to get anymore fish what would you suggest? And is it neccasary that i use Aqualibrium salts? One store told me that i should be using it but is this just a ploy to make me spend more money? I'd appreciate any advice that you could give me, as its clear that you seem to know what you're talking about thankyou

 

[LorLor]

thats no problem, its nice to get some actual decent information! Local pet shops have been rubbish!

Well...my tank is a mere 35 litres!! I was completely ignorant to how difficult tropical fish were to keep and how much room they needed etc, and when i bought my fish i wasn't warned at all, i was just allowed to buy as many fish as i wanted without good advice being given. I really regret the decision now, i wish i'd have waited longer to save for a bigger, better tank and also given myself a good while to read up on everything. I am completely in love with my tank though and will be getting a bigger, better, nicer one as soon as i can.

As for indian fern...sounds like a good plan as i only have a couple of ornamental flowers in there at the moment which really isnt enough cover for my poor guppies. Unfortunately i live in Banbury, dont think its too close to you? But im sure if i have a scout around stores i'll be able to find some. Thankyou for offering though, really kind of you.

Well i had a case of swimbladder in a couple of my fish a few months ago so treated the aquarium with the correct treatment and was advised to use Aqualibrium salts at the same time, which i think is okay, but since then ive just been adding a small amount every water change and wasn't really sure if it were necessary.

And oh dear funny you should mention Bloodworm, i purchased a very overly priced packet last week thinking it would be a lovely treat for my fish. Luckily i havent been feeding it to them every day and have only given it to them about twice since buying it. thankyou for the warning!

Thankyou again for your words of wisdom, feel like im finally learning something!

 

[nmonks]

Happy to help.

35 litres isn't big enough for mollies, and to be honest, not big enough for guppies either. Certainly, male guppies can/will harass any females kept with them in a tank this size.

Indian fern -- Ceratopteris thalictroides -- is easy enough to buy online.

Aquarium salts will do little/nothing for dropsy or "swim bladder problems" (which, incidentally, are usually nothing of the kind). Epsom salt at a dose of about a teaspoon per gallon will help for certain types of swelling, including pop-eye, but that's a totally different kind of salt. Sodium chloride has no impact at all.

Adding salt to a very small aquarium might be beneficial if water quality isn't good. But do be aware that while sodium chloride detoxifies nitrite and nitrate, the downside is that freshwater fish can be stressed by continual exposure to sodium chloride. So there's a trade off. By all means use sodium chloride for therapeutic reasons in the short term, but avoid using it week after week after week.

Freeze-dried foods are poor value because of how much you get for your money. Wet-frozen foods are infinitely better.

Cheers, Neale