A question.

good question.

I have a 75 with approx 5 gallon wet/dry sump.

the wet dry sump has a huge media field for bio media and once the tank cycled the filter quickly adapted to any bio load I added..

this tank has 4 juvie discus, 3 growing angels, 3 keyholes , 2 bolivian rams, a bn and 3 oto's.

It is lightly planted(soon to have more plants in it) ph7.2, 0 ammonia, 0 nitrites, 20ppm nitrates.

I change 20-30 gallons in this tank 3x week.(fish are fed 3xday)

so far no problems. I am waiting to see what happens when the fish reach adult size.

the discus are growing fast and were moved in about 1-2 weeks ago after 3-4 weeks in quarantine.
 
I'me thinking like a 75g divided at the 1/3 point(from front to back, tank will be viewable from both sides) (for my nippy (atleast in my opinion)tetras) and then a 50g refugium that is planted with fast growing plants(and possibly might be used to raise fry). Your tank in my opinion seems a little on the high side as far as stocking goes (even with the sump) but the wet dry should make up for it.
 
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