What species is this?

I’ve tried to match up pics but am not totally sure. I have 4 of the black spotted Cory’s and 4 of the Albinos. I’m also wondering if the substrate is OK for them. They seem to graze ok on it.

The species of the patterned cories is Corydoras paleatus. The albino fish may be the same species, or another, as there are albino forms of a few species available.

Substrate is unfortunately not acceptable for cories. First, they cannot filter feed which is essential (they pick up a mouthful of substrate, filter out any food bits, and expel the substrate via the gills; can't be done with gravel). Second, the larger gravel means food can fall down and the fish cannot get it, and this increases bacterial problems particularly for substrate fish (this is a more common cause of barbel erosion than rough gravel). Third problem can be the roughness; I cannot tell from pho0tos how rough the gravel is, but it is very angular. And even if it feels "smooth" in your hand, it may not be when it comes to the fish's barbels.

Cories need sand, smooth inert sand. Quality play sand works well, or one of the more expensive aquarium sands provided they are inert (some is calcareous).

Thanks Byron.
The substrate came with the tank years ago and of course worked fine for goldfish I was keeping at the time. It's a 125 gal tank so I will have to get a bunch. Hopefully I can replace in-situ without too much trouble. Now to research what to use. I have a few Kleiner Bar Swords and would like to explore more plants, but I want to keep the fish healthy and happy too.

Here is a pic of one of the Albinos

The albinos are C.aeneus

Oblio said:

Thanks Byron.
The substrate came with the tank years ago and of course worked fine for goldfish I was keeping at the time. It's a 125 gal tank so I will have to get a bunch. Hopefully I can replace in-situ without too much trouble. Now to research what to use. I have a few Kleiner Bar Swords and would like to explore more plants, but I want to keep the fish healthy and happy too.

Click to expand...

I have changed the substrates in my tanks more times than I really care to remember, and it is without question a big job, so get it right before you start. For the benefit of the fish, you need a temporary tank (smaller than the display is OK, much smaller even) as you do not want to be rushed (fish sitting in buckets of water is not a good thing for them, and highly stressful by comparison). Live plnts, especially good floaters, will avoid any chance of "cyling" issues.

Byron said:

I have changed the substrates in my tanks more times than I really care to remember, and it is without question a big job, so get it right before you start. For the benefit of the fish, you need a temporary tank (smaller than the display is OK, much smaller even) as you do not want to be rushed (fish sitting in buckets of water is not a good thing for them, and highly stressful by comparison). Live plnts, especially good floaters, will avoid any chance of "cyling" issues.

Click to expand...

It will have to be much smaller than a 125 gal, but I have been thinking of getting an additional small (e.g 29 gal) tank for office area. (Is this what MTS is?) Now that I have my current tank cycled and somewhat stocked, I find myself walking in to enjoy the fish.

A side question:

Is it normal for Corys to rest, perhaps with all their activity they need it from time to time. I suppose it just sets off an alarm to see a fish laying on the bottom when a mid or top level would be chilling up higher.

Water params:

Ammonia 0
Nitrite 0
Nitrate 5
pH 7.2
Temp 78

Oblio said:

A side question:

Is it normal for Corys to rest, perhaps with all their activity they need it from time to time. I suppose it just sets off an alarm to see a fish laying on the bottom when a mid or top level would be chilling up higher.

Water params:

Ammonia 0
Nitrite 0
Nitrate 5
pH 7.2
Temp 78

Click to expand...

If you mean the fish is sitting upright, not a problem. I have some 40 wild cories and they do this as they feel like it. If you mean flopped over on their4 side, that is not normal. Loaches will do this close to dusk, but not cories.

Byron said:

If you mean the fish is sitting upright, not a problem. I have some 40 wild cories and they do this as they feel like it. If you mean flopped over on their4 side, that is not normal. Loaches will do this close to dusk, but not cories.

Click to expand...

Upright and breathing normally, thanks for the info. I should try to take a pic, then they move I've never had Corys so I am new to their behavior.

My Tetras like to steal algae wafers. Bottom fish has wafer in mouth in above pic. They are comical and will chase each other and when the wafer is dropped by the chased fish the pursuer will catch the wafer in mid-water and play keep away.