Green sunfish concerns

[Everything Fish]

Hey guys, long story short I'm getting a 20 gallon long (30" x 12" x 12") tomorrow with a preseeded sponge filter (rated for 50 gal), tons of plants, and seeded gravel so it's precycled. After about a month of debating what I should do, yesterday I really made some charts on the pros and cons of each option and in the end I'm going with: a single green sunfish.

Now I hear so much conflicting info all the time about greens. I'd say about 70% of keepers I asked said go for it, 25% said upgrade later, and 5% said don't do them they're a bad fish.

Regardless I'm going for it whether I'm going to have to upgrade later on or not. This is what I wanted to ask you guys:

Who thinks the fish will be alright in the 20 by itself with weekly 50%s for life?

If you don't think it will be ok for life then what's the approximate time frame I'd be looking at for when I would need to upgrade by?

BTW to give you the details of the tank here they are:

Gallons: 20
Dimensions: 30"L x 12"W x 12"T
Temperature: room temp so 64-80ish (I know 80 is hot but they're hardy sunfish and ones at my local park have lived through the summer where occasionally the water will hit 84 for days at a time!)
pH: 7.6
Lights: 6-8 hours
Decor: lots of native plants, some boiled rocks from my local lake, and driftwood soaked to remove all the tanins

 

[JessiNoel21]

I think if he or she is the only one in the tank it should be fine. Heck I kept a pumpkin seed in a 16 gallon for 5yrs . I feed it live food of night crawlers, feeder fish, flightless fruit flies, superworms, and crickets.

 

[Everything Fish]

Awesome! I'm actually out fishing now but all I'm catching is bluegills and I know they wouldn't last in a 20 for long

 

[Alan26]

i had one by itself in a 55 gallon (started with a couple perch and a smaller gsf...he was too big, messy, aggressive, and destructive...the tank was a constant mess...

...if you're ok, with an empty tank (maybe a rock or two) he will be fine...way to big for that tank, but fine...

...caught him ~8 inches...grew to ~13 inches

 

[henningc]

I've kept both sunfish and blue gill without problems. Keep in mind if you add anything these guys make most cichlids look like whipms. You may have an isse with the plants as it may dig them up. I'd make sure to have some rock structure and driftwood if you can.

I will make a suggestion, go to Jonah's Aquarium and see what they say. They have the pigmy types of sunfish and they are a entirely different story. Six in a 20L with some other natives would work nicely and they won't tear the tank to shreads.

 

[FWFishTanks]

For a green sunfish, I wouldn't go anything smaller than a 40 gallon personally, but since your tank is a 20 long... You should be okay for a while, but he may outgrow the tank in the future.

 

[henningc]

How did it turn out? Did you catch one?????????