Attempting to restart a 20 gallon community tank? - Tropical Fish Keeping - Aquarium fish care and resources
LinkBack Thread Tools
post #1 of 2 Old 12-05-2010, 05:03 PM Thread Starter
New Member
victoria8674's Avatar
Attempting to restart a 20 gallon community tank?

Long story short, i had a green spotted puffer and a figure 8 puffer, who both died within a month, most likely from IP's because i didn't treat them soon enough. So, i'm now left with
  • an empty 20 gallon tank
  • a bunch of instant ocean salt
  • tons of frozen bloodworms.

I'd like to set up the tank again. At first i thought, oh, i'll go with full saltwater and start from there. However, after doing loads of research, i figured i'd better not jump right into that. (I have 4 freshwater tanks set up, but my first attempt at anything brackish/full saltwater was the puffers and obviously that didn't go as well as i had planned.)

I need suggestions on fish that are 'easy' to keep, and preferably community fish.

Also, what do i need to do to use the gravel, plants (fake) and hiding places from the puffer tank? I'd imagine i have to do something because they were in brackish water.......


2.5 gal, juvenille female convict cichlid
6 gal, dwarf african clawed frog
10 gal, convict cichlids
10 gal, empty.
20 gal, empty.

bird: green cheeked conure
and a chubby old cat :)
victoria8674 is offline  
Sponsored Links
post #2 of 2 Old 12-13-2010, 02:13 AM
bettababy's Avatar
You have an ideal situation here for learning saltwater gradually with the same fish starting out in brackish conditions. Mollys, especially the sailfin mollys do wonderfully in brackish water and can be acclimated to full saltwater if it is done slow enough. Yes, I have done it and I have taught others to do it as well.

One thing to be careful of is population. Working with all the same sex is important if that is the only tank you have available for them, unless you have an outlet that will take the fry when they are very small. Mollys tend to grow almost double in size when kept/raised in brackish water from a young age to adult. The last ones I worked with were silver sailfin mollys and the adults were about 5 - 6 inches long at full grown, and their fry were much larger than the average molly fry as well. 20 gallons would not give you much room for even 1 full spawn on a temporary basis. The good news is that 2 females or 2 males are perfectly compatible together long term, which helps to avoid breeding.

To start this out, rinse everything very well with plain fresh water, set up the tank and get it cycled. Start out as freshwater, introduce the mollys and gradually add salt content with each water change until you reach brackish conditions. There is no limit to the range mollys can tolerate in brackish conditions, so work them up to whatever you are comfortable with and then maintain it there for 1 - 2 months. After 1 - 2 months, slowly increase spg/salinity with each water change until you reach full saltwater conditions. Mollys do real well at 1.023 spg/salinity, which makes them compatible with many of the peaceful small marine fishes such as shrimp gobies, oscellaris clownfish, and many of the shrimp species. The only warning is not to mix mollys with corals as they tend to pick at and/or eat most of them which will damage and kill the coral. If you go this route, to convert to a marine tank and allow room for other tank mates, a larger tank would then be needed.

This is an easy way to learn the ins and outs of saltwater, and if you decide its not for you, its easy to slowly reverse the salinity and take it back down to freshwater conditions in the same manner you worked it up to saltwater to begin with.

Mollys tend to be healthier in brackish water than in either fresh or full saltwater, but healthier in saltwater than in fresh. Many of the common illnesses found today in the standard molly can't survive in a brackish or saltwater environment. The salt also acts as a boost to the immune system of mollys.

Other small brackish water fish that I have always loved were orange chromides and bumble bee gobies, but I think my all time favorite in the brackish fishes is the Indian glass fish (Parambassis ranga). Most often they are sold as freshwater fish but, like the mollys, they thrive best in brackish conditions... (their range of brackish is a bit smaller than that of the molly) If they are purchased as freshwater fish then moving them up to brackish should be gradual like I explained for the mollys.

You have a lot of options open to you. I hope this helps.

Dawn Moneyhan
Aquatics Specialist/Nutritionist
Juneau, WI
bettababy is offline  

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

Similar Threads
Thread Thread Starter Forum Replies Last Post
45 gallon community tank Salix Freshwater Journals 6 11-04-2010 10:31 PM
55 Gallon Community Tank StBDawg Freshwater and Tropical Fish 9 02-21-2008 04:43 PM

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