Starting new tank, how long can fish stay in a bag? - Tropical Fish Keeping - Aquarium fish care and resources
LinkBack Thread Tools
post #1 of 5 Old 03-28-2013, 09:18 PM Thread Starter
New Member
Starting new tank, how long can fish stay in a bag?

So I've cycled my new 20 gallon tank, and I want to place mollies and swordtails together. I have two questions, though.

I've gotten mixed messages on whether this is a good idea; some say they're great together, others say it was awful. Will the two work well together?

Also, I was thinking of 4 mollies and 2 sword. How long should these be in a bag, as I might have to leave them in the car for up to 3 hours? Is there anything I can do? Plus, I've read that they can last anywhere from half an hour to five days. Any advice?

Thanks for all your help!

Last edited by CynicalSmile; 03-28-2013 at 09:35 PM.
CynicalSmile is offline  
Sponsored Links
post #2 of 5 Old 03-28-2013, 09:45 PM
MoneyMitch's Avatar
well fish are shipped by mail usually next day air so 3 hrs should be fine as long as they arent left in extreme cold or heat. they can handle cooler then normal or warmer then normal but not extremes.
MoneyMitch is offline  
post #3 of 5 Old 03-29-2013, 08:41 AM
Welcome to TFK!

I think it's generally held that fish can survive shipments in bags for 24 to 48 hours, but these are larger bags than typical pet store bags. You should be fine at 3 hours but as mentioned, make sure the temperature in the car won't get extreme. When I go for fish I often take a cooler (winter or summer) to moderate and insulate against the outside temperature. In winter I put a container of warm water in the cooler.

As to Mollies and Swordtails together I'm not aware of any problems but have no first hand experience. I did have some Mollies and Platys together once and they were okay.
You may have an issue with your numbers of fish unless you're getting all females. Live bearers do best when there is one male for every two females, otherwise the male tends to pester one female way too much.

Father Knows Best but Abbey knows everything! I once knew everything, then I asked one question.
` •...><((((º>` • . ¸¸ . • ´` • . . . ¸><((((º>¸ . • ´` • .. . ¸ ><((((º>
AbbeysDad is offline  
post #4 of 5 Old 03-29-2013, 09:07 AM
fish monger's Avatar
Some shops fill their bags with oxygen and some with compressed air. Naturally, the oxygen would give you more time insofar as respiration is concerned. As has been mentioned, temperature is a major consideration. Just make sure that the temperature in the car is kept at a moderate (mid seventies) range. In any event, get them home as soon as possible. As AbbeysDad said, be sure to get at least a 1 male to 2 female grouping.

fish monger is offline  
post #5 of 5 Old 03-29-2013, 06:38 PM
Byron's Avatar
Welcome to Tropical Fish Keeping forum.

The best way to deal with the temperature in transit is to get yourself one of those picnic-type coolers. They come in various sizes and are not not expensive. Not only does this maintain a steady temperature, but it adds darkness which is almost as important. Fish in transit will be more calm if it is dark, total blackness, around them.

Tell the store the length of time involved. Some of the better stores will increase the bag size, add extra oxygen, etc. I would not delay getting them home any more that is absolutely necessary. Fish secrete pheromones and allomones and these can build up in the water, along with the ammonia of course. And molly are very highly sensitive to ammonia at very low levels.

To the question of swordtails and molly, in a 20 gallon the answer is no. Swordtail requires a larger tank as it is a larger fish and needs space to swim. Check the profile, click the shaded name. The Common Molly also gets a decent size, and in a 20g high I would not have more than 3. All male is fine; one female in with one or more males will mean hundreds of fry regularly, and getting rid of them is not always simple.


Byron Hosking, BMus, MA
Vancouver, BC, Canada

The aquarist is one who must learn the ways of the biologist, the chemist, and the veterinarian. [unknown source]

Something we all need to remember: The fish you've acquired was quite happy not being owned by you, minding its own business. If you’re going to take it under your wing then you’re responsible for it. Every aspect of its life is under your control, from water quality and temperature to swimming space. [Nathan Hill in PFK]
Byron is offline  

bag , mollies , new tank , tetras

Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page

Similar Threads
Thread Thread Starter Forum Replies Last Post
How long could a koi and goldfish stay in a 20G long tank? Ulyaoth Cyprinids and Atherinids 2 10-19-2011 10:27 PM
Plecos - How long can zucchini stay in a tank? DKRST Catfish 4 08-12-2011 09:02 AM
How long does a tank stay cycled w/no fish? aunt kymmie Beginner Freshwater Aquarium 25 03-28-2010 01:58 AM
How long can a fish be in a store bag for? Major25 Freshwater and Tropical Fish 2 02-10-2010 07:18 AM

Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

For the best viewing experience please update your browser to Google Chrome