Stocking New 300 Gallon

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Arrow1oo

Feeder Fish
MFK Member
Mar 8, 2025
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Florida
I’ve been lucky enough to finally get my hands on a 300 gallon tank (8’ long x 2’ wide x 29” high).

I intend on running the largest sump I can fit, and my water is neutral and leans slightly to the softer side.

Before this, I’ve kept two traditional planted tank and one Mbuna tank. I’m fighting my instincts and trying to do something a bit different with this one and take a shot at some bigger, more personable fish.

Because this is smack at the entrance of my home, I do also need it to be a showstopper tank.

So far, im relatively certain I want:

2 (or more) oscars
2 (or more) severums

Beyond that, I’m pretty flexible and looking to see what the experts here suggest.

I also love the idea of keeping a starry night cichlid but I’m not sure if that is possible, if not I can let it go.

My goal here is to figure out my stocking list that’s both functional and really attractive looking. I most likely will include some artificial silk plants just for some small pops of green (I will try to establish some bigger swords and anubias/java fern but I know there’s no guarantee especially with severums).
 
Hmmm, you don't want it too over crowded but "maybe" the 2 oscars, 4-6 mouth brooding severums and a group of jarupuri for the bottom.
Or change the stock up a bit for possibly festivums?
 
Hmmm, you don't want it too over crowded but "maybe" the 2 oscars, 4-6 mouth brooding severums and a group of jarupuri for the bottom.
Or change the stock up a bit for possibly festivums?
That doesn’t sound too bad. Few quick questions about this:

1. If I cut down on the severums can I include a different type of cichlid? Not really even sure what type, maybe electric blue acara or fire mouths or something. Just to add variety

2. Are jarapuri interchangeable with Geo’s in this situation? Something like tapajos or other variations.
 
That doesn’t sound too bad. Few quick questions about this:

1. If I cut down on the severums can I include a different type of cichlid? Not really even sure what type, maybe electric blue acara or fire mouths or something. Just to add variety

2. Are jarapuri interchangeable with Geo’s in this situation? Something like tapajos or other variations.
You could go with tapajos or even sveni to swap out the jarapuri.

The mouth brooding severums can reach almost a foot. OR could go with heros sp. red shoulder severums as they'll stay on the smaller size of 8 inches roughly along with andinoacara pulcher (original blue acara that look like mini green terrors).

Firemouths are a cichlid from Central America that thrive in high ph hard water.
 
You could go with tapajos or even sveni to swap out the jarapuri.

The mouth brooding severums can reach almost a foot. OR could go with heros sp. red shoulder severums as they'll stay on the smaller size of 8 inches roughly along with andinoacara pulcher (original blue acara that look like mini green terrors).

Firemouths are a cichlid from Central America that thrive in high ph hard water.
I’m embarrassed had no idea there were two different species of severums in the hobby.

I think I might go with the smaller red shoulder and those color morphs as well as the acaras you mentioned.

Also embarrassed I didn’t know firemouths were CA cichlids.

With this info, what stocking numbers would you suggest with Oscars, red shoulder severums, acaras and geophagus?

Also, and sorry to keep asking, but are there any other species I should consider? I’m assuming the polleni might just be too big and too mean to be in this tank which is fine.

Very much appreciate your help
 
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I’m embarrassed had no idea there were two different species of severums in the hobby.

I think I might go with the smaller red shoulder and those color morphs as well as the acaras you mentioned.

Also embarrassed I didn’t know firemouths were CA cichlids.

With this info, what stocking numbers would you suggest with Oscars, red shoulder severums, acaras and geophagus?

Also, and sorry to keep asking, but are there any other species I should consider? I’m assuming the polleni might just be too big and too mean to be in this tank which is fine.

Very much appreciate your help
All good. Were here to help.

I try and keep things biotope correct and know polleni is Madagascar and I don't have any experience with them. Maybe some others can chime in.
With an 8ft tank, I would do the 2 oscars, 4-6 red shoulder severums, 3-4 blue acaras and 6-8 tapajos or 6 sceni
 
All good. Were here to help.

I try and keep things biotope correct and know polleni is Madagascar and I don't have any experience with them. Maybe some others can chime in.
With an 8ft tank, I would do the 2 oscars, 4-6 red shoulder severums, 3-4 blue acaras and 6-8 tapajos or 6 sceni
Appreciate it. From my research, since there aren’t many Madagascan fish in the hobby I’ve seen people say they tend to not be too aggressive with Oscar’s/severums and what not.

I also saw that they come from so many collection points in Madagascar that they can tolerate more acidic SA water.

Either way, thanks for the info
 
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All good. Were here to help.

I try and keep things biotope correct and know polleni is Madagascar and I don't have any experience with them. Maybe some others can chime in.
With an 8ft tank, I would do the 2 oscars, 4-6 red shoulder severums, 3-4 blue acaras and 6-8 tapajos or 6 sceni
Hey Roger, had another random question. What are your thoughts on increasing the amount of Oscar’s and decreasing the severum count?

I know 3 might not be a great number since the runt might get picked on hard, but what about 4? Is the tank size not enough to sustain that? Will aggression be too much of an issue?
 
Hey Roger, had another random question. What are your thoughts on increasing the amount of Oscar’s and decreasing the severum count?

I know 3 might not be a great number since the runt might get picked on hard, but what about 4? Is the tank size not enough to sustain that? Will aggression be too much of an issue?
Personally if I had to do it, 2 oscars max. But that's just me. If you decide, maybe 3, but get all of them at same time and size. Add lots of structure to the tank for line sight breaks.
 
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