How much to feed brackish columbian catfish?

[flipz]

FOR BACKROUND, READ THIS. FOR JUST MY QUESTION, SCROLL DOWN:
Hi all. For the past year I've had a tank with 2 columbian catfish (black-fin shark, white-fin shark, etc). I had 1 that was always slightly bigger than the other, and since pretty much day 1 the larger one picked on the smaller one. So the smaller one was always sick, for no apparent reason other than stress. After about 2 months we had to seperate them, then every few months we would try putting them back together, and it wouldn't take more than a day or 2 for the larger one to start picking on the smaller one again. And by larger i mean barely. The small one grew to be about 3.5", and the large one maybe 3.75.

There is plenty of current, plants, places to hide, etc. Well out of no where a year later (when seperated) the smaller one went crazy one night. Don't know how to explain it but she just kind of freaked out, started bouncing off the glass like she was blind, and then ate gravel until she died.

Well anyways, to make a long story short, we are going to be purchasing and adding another columbian catfish, however at this point the larger one is about 4" and the largest one at any store we have been to is approx 3", and they are a lot skinnier. From what I have read these fish aren't aggresive, however I'm afraid to even put them together. What can I do to stop the larger one from picking on the smaller one? I've read about some catfish that if you don't feed them enough, they will go looking for food, and basically eat anything in the tank. So I'm thinking that could explain it. So how much am I supposed to be feeding them? My pet store told me once a week is fine, however I personally have found that every other day keeps them happy. At one point I was feeding them everyday and it made my nitrate levels go way up.

I want to keep her well fed, so she leaves this new one alone and lets it grow some. She eats... a LOT! Her stomach literally has a bulge when she is done eating. She will eat food until it won't even go in her belly anymore. We will treat her to feeder guppies sometimes, and she'll eat 2-3, and have the hugest bulge in her stomach, and still try going for more.


AND THE QUESTION IS:
Sorry for all the rambling! Haha. Basically my question is, how much and how often should I be feeding them? Thanks everyone!!

-brent

PS- If it makes any difference, they eat a wide variety of food: sinking pellets, shrimp, blood worms, live fish, flakes, etc

 

[Allivymar]

They should be fed once or twice a day tops. Most fish will continue to eat after they are full; what happens is the extra food isn't digested. So all it really does is come out the other end and mess with water parameters.

 

[Menagerie]

[center:b698ae8e6d] Welcome to AA, flipz! [/center:b698ae8e6d]

Fish will eat until they can't eat any more--I would cut down on the food. There is no reason for the belly to bulge. I have never owed columbian catfish, JMHO, but it sounds like you are feeding too much at once.
From liveaquaria.com:

Setting up a tank to match its natural environment will require plenty of plants and rocks. Since it grows quite large, starting with a minimum tank size of 70 gallons is recommended. As the Columbian Shark grows larger, there is a chance that the shark will eat smaller tank mates.

How large is your tank?
As for what happened to the last one, that may never be solved. Someone that owns these catfish will come on and give you more advice.

*Edit--I think once every two days is fine for catfish. My catfish and African cichlids are fed every other day and are doing well, as are the water parameters.

 

[flipz]

Thanks so much for the welcome, and the replies!

As far as feeding them too much (because of belly bulge) I don't want to disagree with you, considering you have over 1000 posts... haha. But even if all she eats is 1 sinking pellet, broken in half, her belly will bulge. And we were just at the pet store today and the lady commented how she loves feeding them because they go so crazy for food, and then they get those cute bulges.

So... with that I would guess I'm not feeding them too much, but who knows. Haha. As long as they are happy, and the levels in the tank are good, I'll stick with it.

Thanks for the advice though!

-brent

 

[Pufferpunk]

Wow, those fish get to be 18"! Do you have a huge tank in their future?

 

[flipz]

In their future yes. hehe. Unfortunatly right now the 1 columbian catfish (and added last night a spotted puffer, they seem to be getting along great!!) are confined to a 25g tank, because my fiance and i are both in college, so we move around a lot. But starting next year we will have a house, and we already know the first thing we are buying is a 100g+ tank! So they will be happy fish then.

-brent

 

[Menagerie]

Ew, I don't think I could live with a fish that has a belly bulge. I have seen pics of puffers with that and JMHO--it's not pretty.
As for 1000 posts, I just like to chat with fellow hobbyists. I am learning just like everyone else