What do you think?

Bob57

Since yesterday that I visited a LFS,I changed my mind.I was planning in a 75 gallons set up,now I want a 48 gallons rimless tank(looks much nicer).
My doubt is in the quantity of fishes I want to stock it with.I plan in a school of 25 to 30 cardinal tetras and later add 5 to 7 wild Peruvian Scalare.
The tank will have sand,a few stones and driftwood-something very similar to the photo in my avatar-no plants,a canister filter and moderate light.
Is the quantity of fishes that I plan to stock safe for a 48 gallons(36"x18"x18") or is too much?
I have kept fishes in the past ,but this is my first project really aesthetically pleasant.

Byron

You will absolutely need a 4-foot tank for the wild angelfish, but I would move up to a 90g. A group of fish reaching 8+ inches in height and 6+ inches in length need that space.

I would not have Cardinal Tetra with them, they will get eaten esp by wild angels.

With either species, floating plants would help a lot. I recognize the authentic biotope idea with sand and branches, and that is excellent; but these fish occur in very dim water due to thick overhanging and/or floating vegetation. Water Sprite is ideal for this, the dangling roots with the branches will be very authentic.

Here's a video I posted previously; I know they are altums, but the habitat is the issue.

Bob57

Byron,the video is excellent,thanks!That is what I'm aiming for,a biotope or the closest to it I can reach.I will use even peat moss for the tannins discoloration of the water and benefit of the fishes.The lighting will be hanging from the ceiling,at a distance where it is comfortable to see them,yet it won't provide excessive lighting to them.The Water Sprite is an excellent idea.I can get a bagful for almost nothing or for free at the farm where the fishes will be ordered.
I never tried them,but what about lemon tetras?These are bigger and have a deeper body,less prone to become a fast meal to the angels.Do the lemons share the same biotope as the angels?Same water and light conditions?No need for planted tank?
I think 90 gallons is a bit excessive for me,financially and living on a second floor,I fear for the neighbor downstairs.
Maybe 75 gallons will be a good compromise between.Isn't it?

Byron

It is possible the Lemon Tetra and angelfish occur together, the former occurs in the Rio Tapajos basin (a southern tributary of the Amazon in Brazil) and the latter in the Amazon basin (including the Amazon itself in places) though primarily in norther tributaries I suspect. Still, suitable together. The other Hyphessobrycon species also make good tankmates for angels, being disk-shaped. The rosy clade is especially good, fish like the Roberts Tetra, Rosy Tetra [these add a nice reddish colour to the tank], Black Phantom Tetra and Red Phantom Tetra, and others. Not Serpae Tetra though, will nip fins.

A comment on the light hanging from the ceiling. If there is any visible space between the fixture and the tank, the light will shine in your eyes and not be conducive to viewing. For this reason, unless the light is somehow enclosed, having the fixture directly on the tank frame is best. All you need to do is select a single tube T8 fixture, or even a dual tube, but only T8; T5 is far too bright. Then floating plants. Water Sprite will easily cover the surface, I have done it, and the tank below is very dark. You can thin it to your liking. Some Brazilian Pennywort planted in the rear corners would frame the scene nicely, and be authentic, replicating hanging vines. This plant complements angelfish nicely.

The 75g should work, at 4 feet length. The sand substrate will be thin, only an inch or less, more a sprinkling. Playsand from Home Depot is ideal, it is very close to the colour of the sand in the Rio Negro basin so very authentic for angels. Some corydoras would be nice too. You will have wild angels, so they need warmth, 80-82F minimum. Your tetra will have to manage with that, so check the temp ranges in the profiles. Corydoras sterbai do fine at these temps, most other corys would burn out.