Catfish stocking densities

[Kobus Jooste]

I am taking a look at fish other than tilapia for a proposal.  Koi has got enough info for me, but as there are many people here with practical experience with catfish, I'd like to find out what recommended AP ratios of catfish stocking densities (fish to cube of water) could be.  In South African commercial aquaculture operations, our local catfish (Clarias sp.) can be pushed to phenominal densities but I need to try to figure out what feasible densities for aquaponics would be.  Anyone here with knowledge of stocking densities for large systems using catfish?

[TCLynx]

Do you have any links to info on the Clarias sp?  Catfish have such a wide range of types that I'm certain the channel catfish space and filtration requirements are probably only applicable to Channel, White and Blue catfish.  Even here in the USA there are Bullheads that are such a different catfish that the numbers I'm used to using don't apply to them.

[Kobus Jooste]

I'll go scratch in FishBase, but am not sure what info you need.  I have heard of 300 kg/ 1000 liter of water upwards to almost double that in intensive aquaculture.  Species is sharptooth catfish, Clarias gariepensis.

TCLynx said:

Do you have any links to info on the Clarias sp?  Catfish have such a wide range of types that I'm certain the channel catfish space and filtration requirements are probably only applicable to Channel, White and Blue catfish.  Even here in the USA there are Bullheads that are such a different catfish that the numbers I'm used to using don't apply to them.

[Chi Ma]

These look pretty dense. LOL.

 

[Harold Sukhbir]

Hi Kobus,

Are you looking to go over the AP ratios for fish for your proposal? Is it AP with more of a  focus on fish production?

[Kobus Jooste]

Harold - I need to develop stocking ratios for as many fish as possible.  Right now I have ratios for tilapia.  I can work out koi but was getting a bit stuck on catfish.  I'm also hoping to work on a range of options (same as for tilapia) that goes from UVI high density theory down to Friendly level low density rates.

Harold Sukhbir said:

Hi Kobus,

Are you looking to go over the AP ratios for fish for your proposal? Is it AP with more of a  focus on fish production?

[Carey Ma]

Hi Kobus,

I know you are busy and don’t mean to throw a wrench anywhere but I’m curious.

I know what you are doing and why you need numbers; so put some pretty numbers together for them bean counters that support your project and we can find technical answers after you get funding. (However, I’m not sure why you need info on so many types of fish unless it is a super AP center or is it to reference ROI)?

 

These numbers are kind of (almost totally) arbitrary in my opinion, due to the many variables one has to be concerned with and would take a serious algorithm to figure all that data per location. To me, stocking density is only a guide of where trouble begins.

 

It is my understanding that fish can have good or bad health and welfare at high and low stocking densities, all dependent on local conditions. Even the type of system you use will affect the stocking ratio.

 

Are you trying for maximum density or a comfortable midpoint where it is economically feasible? Or are you trying to determine the nutrient output capacity?

 

Sorry, I hate to guess but can’t help myself.

 

Cheers

[Kobus Jooste]

Carey - In South Africa we run a nasty gauntlet with aquaculture.  The fish is worth little on the market, and the power is expensive.  There is one or two food manufacturers and they do not give their stuff away on the cheap either.  I have built a complex spreadsheet with feeding ratios, stocking densities and stocking duration.  This gives you a clear idea when the fish is getting more input than what they are worth.  I have done this for a tilapia HD system and now want to do the same for a koi LD and catfish LD configuration.

 

When it comes to fudging numbers I have spent enough time in science to make it look right, but for my own mind, I want to do this.  HD aquaponics UVI style in South Africa cannot wiork right now.  I have re-designed a complex (10 greenhouses) to function on LD friendly Aquaponics stocking densities to begin with with some koi grow-out as a secondary fish stock.  I will only do the modelling of everything in detail if I get paid to do it, but I am scratching around for info as neither UVI nor Friendly Aquaponics uses catfish in their examples (not those that I have). 

Carey Ma said:

Hi Kobus,

I know you are busy and don’t mean to throw a wrench anywhere but I’m curious.

I know what you are doing and why you need numbers; so put some pretty numbers together for them bean counters that support your project and we can find technical answers after you get funding. (However, I’m not sure why you need info on so many types of fish unless it is a super AP center or is it to reference ROI)?

 

These numbers are kind of (almost totally) arbitrary in my opinion, due to the many variables one has to be concerned with and would take a serious algorithm to figure all that data per location. To me, stocking density is only a guide of where trouble begins.

 

It is my understanding that fish can have good or bad health and welfare at high and low stocking densities, all dependent on local conditions. Even the type of system you use will affect the stocking ratio.

 

Are you trying for maximum density or a comfortable midpoint where it is economically feasible? Or are you trying to determine the nutrient output capacity?

 

Sorry, I hate to guess but can’t help myself.

 

Cheers

[James Casey Brown]

I only use catfish and bule gill i have had one system going for over  a year now and the second on about 3 months .you got to keep the water timp between 75 to 80 degrees.or they will get ick easy.i usely stock 50 fingerlings fish at a time and harvest to heavy eaters and they come to size it seams to be the best # for a 300 gal system

 

[TCLynx]

I've never seen Ick in my catfish, then again I've never seen in in any fish I've had so I guess I've just been lucky.

 

Now there are other diseases that can hit catfish pretty hard. Columnaris being the most common since the bacteria is present in almost all fish water.  The trick is to avoid stressing or handling the catfish too much, especially when the water is cooler and definitely make sure not to over feed while the water is still below 75 F or I should say just make sure not to over feed period since I've had flare ups of it when I was a way and the weather was warm too.  I don't heat my water for my channel catfish and they do fine through the winter as long as they are big enough to go hungry when winter comes.  I don't think I've seen any rise in illness in them due to cold water.  It seems they were far more prone to getting sick as the water temperature comes up and feeding resumes, I expect that 68-75 F temp range is a danger zone since the tendency is to want to feed more than is really appropriate for the temperature.

 

Now I did once stock about 45 channel catfish for grow out into a 300 gallon tank and they were looking really crowded as they got big, maybe it's cause I tend to grow them out big.  I currently have about 85 in my tower system 300 gallon tank but they are still mostly small and I will probably move most of them to the big tank once the monsters are all harvested.  I kinda like 10 gallons of fish tank per channel catfish for my big grow out though I know they can do well enough in much higher stocking, especially while they are small.

[James Casey Brown]

i feed mine year around so i can grow year around so i keep them between 75 and 80 and everything grows well plants and fish i harvest pan size catfish as they are the best to me i work hard to fatten  them up  why starve them in the winter?
TCLynx said:

I've never seen Ick in my catfish, then again I've never seen in in any fish I've had so I guess I've just been lucky.

 

Now there are other diseases that can hit catfish pretty hard. Columnaris being the most common since the bacteria is present in almost all fish water.  The trick is to avoid stressing or handling the catfish too much, especially when the water is cooler and definitely make sure not to over feed while the water is still below 75 F or I should say just make sure not to over feed period since I've had flare ups of it when I was a way and the weather was warm too.  I don't heat my water for my channel catfish and they do fine through the winter as long as they are big enough to go hungry when winter comes.  I don't think I've seen any rise in illness in them due to cold water.  It seems they were far more prone to getting sick as the water temperature comes up and feeding resumes, I expect that 68-75 F temp range is a danger zone since the tendency is to want to feed more than is really appropriate for the temperature.

 

Now I did once stock about 45 channel catfish for grow out into a 300 gallon tank and they were looking really crowded as they got big, maybe it's cause I tend to grow them out big.  I currently have about 85 in my tower system 300 gallon tank but they are still mostly small and I will probably move most of them to the big tank once the monsters are all harvested.  I kinda like 10 gallons of fish tank per channel catfish for my big grow out though I know they can do well enough in much higher stocking, especially while they are small.

[TCLynx]

I don't have a greenhouse and even when I did I wasn't about to heat it.  Even then here in FL the catfish only went off their feed for a short time when the water gets down below 55.  Also, I'm rather partial to the wintertime veggies here and when trying to use a greenhouse to help keep the water warm in a flood and drain system, it essentially made growing almost everything impossible during the cold spells since it would still get cold in the greenhouse at night and in the daytime trying to recover heat would cook all the cold weather crops.  Last winter without the greenhouse was the best for me cause the veggies like broccoli loved it and since my water is good and warm most of the year, the catfish grow out fast anyway so January doesn't matter that much in the scheme of things.

[TCLynx]

Hay Jonathan,

     I think it has mostly to do with as the temperature is warming up, there is a tendency to try to feed as much as possible to get them growing fast but sometimes the temperature fluctuates and will drop back a bit and the fish might not eat the same amount that day but if careful attention is not paid to if they eat it all up......  it can result in over feeding.

Now keep in mind I learned this information from some one involved in Channel Catfish Farming on a large scale so they don't necessarily sit at each pond for 20 minutes waiting to scoop out uneaten feed.  He said that culumnaris disease does tend to flair and be worst when the water is below 80 F in the spring and there is a tendency to over feed as the water is warming.  Apparently over 80 F the disease might be a little weak and the fish stronger.  I'm not really sure.

But the real thing to watch for is that you are not leaving any uneaten feed around to pollute their water.