Corydoras feeding plan in a community aquarium

[Beastije]

Hi guys

for years I have struggled keeping corydoras, and I think a big part of the problem is my feeding. I am a sparse feeder and assumed they will get their fill of some things, but in community tanks, all the schooling and upper level fish are gluttons that are not afraid to dive under decor to gorge themselves (looking at you rummynose tetras and pearl gouramis). I also feed a lot of small live foods and I simply think they were not good at catching that.



I bought a new group of corydoras, because I missed them, and while the tank may not be the very best for them (has some pebbles, but the previous were all sand and they still died), I really need a detailed help how when and how much to feed them, ideally with pictures, like for a dummy



Here is what I have:
live food - microworms, (new) grindall worms culture, hatched bbs, occasional live mosquito larvae
frozen - cyclops, rotifers, daphnia, brine shrimp, mosquito larvae, blood worms, tubiflex, mysis
dried - hikari micro pellets, dennerle nanogran, sera vipan fry food, jbl novo tabs, local brand, vibra bites, pure spirulina tablets ( bought them for myself, yuck, fish appreciate them better), repashy super green, hikari cichlid gold, dried daphnia. None of these have insect content or any high percentage of it, cause fluval bug bites is impossible to buy here and the only other insect brand dry food has been out of stock for months.

The way I feed my community tanks is I usually combine smaller foods with larger foods. For example I will defrost cyclops and mosquito larvae, squirt the cyclops to entertain the faster feeders and target feed the mosquito larvae. This is how I did this in this particular tank before I added the corydoras. Or I would do the micro pellets and the vibra bites that would fall to the bottom. Or spirulina tablet, crushed to many smaller pieces, and a microworms/bbs.

The tank inhabitants are: 5 adult platy fish and many babies, 5 panda garra (that I target fed with a dripper the mosquito larvaes into their mouths to ensure they get something before the platies) and now 16 corydoras, a mix of 8 panda and 8 black Venezuelan

So please, tell me how often, how much and what to feed my new fish to also feed the other fish and to not have them eat it all, and to not be too small to fall too down between the pebbles...?

Thank you!

 

[GaryE]

The pebbles. Right away, you have a problem there. If we put aside the natural needs of Corys as sand sifters, we also have exposure to pollution as an issue for fish that hug the bottom. Pebbles are a food trap, and ammonia will leak out. It will directly affect these substrate needing fish. I was going to write 'substrate loving', but they need the right substrate. They're eartheaters, as much as Apistogramma or geophagus are. It's in the form of their bodies.

You've noticed the Cory group doesn't lunge at food as it falls. When I feed live to my Corys, they don't get it right away. Their feeding method is to work the sand, grabbing worms and insect larvae that live in it. They don't scavenge or clean up in nature. They hunt a different zone than shoalers. When they eat the live foods we give them, it's when it has settled on the bottom. They get right on to white worms or grindals, because they act like the food they're adapted to hunt. But those are rich foods given occasionally, or to condition breeders.

I find small sized insect or black fly larvae pellets to be excellent for them. They sink fast and get past the shoalers, who can be drawn to another corner of the tank with a flake food given right before the pellets go in. But if the pellets fall between the pebbles (it all depends on the pebble size), then your Corys are in trouble.

I have a mental image of rounded river pebbles about one cm in size, which another member has in one of his tanks. I hope I'm wrong.

 

[Beastije]

The pebbles. Right away, you have a problem there. If we put aside the natural needs of Corys as sand sifters, we also have exposure to pollution as an issue for fish that hug the bottom. Pebbles are a food trap, and ammonia will leak out. It will directly affect these substrate needing fish. I was going to write 'substrate loving', but they need the right substrate. They're eartheaters, as much as Apistogramma or geophagus are. It's in the form of their bodies.

You've noticed the Cory group doesn't lunge at food as it falls. When I feed live to my Corys, they don't get it right away. Their feeding method is to work the sand, grabbing worms and insect larvae that live in it. They don't scavenge or clean up in nature. They hunt a different zone than shoalers. When they eat the live foods we give them, it's when it has settled on the bottom. They get right on to white worms or grindals, because they act like the food they're adapted to hunt. But those are rich foods given occasionally, or to condition breeders.

I find small sized insect or black fly larvae pellets to be excellent for them. They sink fast and get past the shoalers, who can be drawn to another corner of the tank with a flake food given right before the pellets go in. But if the pellets fall between the pebbles (it all depends on the pebble size), then your Corys are in trouble.

I have a mental image of rounded river pebbles about one cm in size, which another member has in one of his tanks. I hope I'm wrong.

It is river sand, in the front there are pebbles, under the plants in the back there is just sand. I lifted the moss and the Anubias so there is a gap between that and the substrate for them to move in.

I can remove a few stones here and there to create less of pebble sea and more of a spotty stones. Would that be better?

 

[GaryE]

That would work. I thought it was all pebbles, but pebbles on sand/gravel is good. You'll be fine.

 

[Innesfan]

I'm not convinced this is about food. What are your water parameters and temperature?

 

[Beastije]

I'm not convinced this is about food. What are your water parameters and temperature?

For sure that is possible. My ph is 7, I don't measure much other than NO2 and ammonia which are 0, and I keep the temp at 25°C, I for sure lost some due to protozoan infection after introducing a new batch (after quarantine!!!) of corydoras that wiped half of the previous group but none other fish in the tank.

In 2021 I bought 15 sterbai, a year later I had 10, bought 10 more, different breeder and by 2025 I have lost all one by one by one.
I attempted with five juvenile paleatus in a different tank no heater, bought them 08/24 and kept losing one by one until 01/25. That tank was fed exclusively microworms and BBS and once a week some pellets. All fish that died had sunken bellies in, like a hole between the plates and different darker color. Hardly ever was there a fungus or snout abrasions. There are some threads around from 2022 where I described the situation that within three months wiped 10 sterbais and nothing I did helped. But I didnt ever treat for parasites.