Stocking for 400 Gallon concrete pond

lulumallick

Feeder Fish
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Nov 6, 2018
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There are the rarest exceptions but as a 99.99% rule, these rookies end up sickening and losing most or all of their fish.
Thanks, I got your point. Just guide me what kind and how many fishes I should keep in that 400g.
Well I am speaking of DIY-ers and people on a limited, average budget. If you are rich (I can see those are real diamond earrings), you could fall into the golden exception group haha, teasing yah a bit.
Yes those are real. But I have limited budget.
I also like DIY things. And definitely continue this hobby.
 
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thebiggerthebetter

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Hello everyone,
I have created a 400 gallon concrete pond (6'X3'X3'). I want to stock some predator fishes. In my LFS there are some spotted gars (18inch & 3-4inch), silver arowana (5-8inch), small RTCs (2-3inch), Oscars (small to large). Besides this I have also raised 2 Oscars from baby to 10inches in 2 different 75 gallon tanks. So my question is can I raise these kind of fishs in my 400 gallon ? Please give me the stocking ideas.
Thanks, I got your point. Just guide me what kind and how many fishes I should keep in that 400g.

Yes those are real. But I have limited budget.
I also like DIY things. And definitely continue this hobby.
Great!

So, what's your experience? What have you already kept and for how long and in what tanks / ponds? Or does your OP describe your entire experience of significance - two oscars to 10" in two 75 gal tanks?

Ok, 6'x3'x3' pond, 400 gal... As RD stated, describe the filtration and aeration, please, water change schedule, etc.

Is it indoor or outdoor pond, what will be the pH, hardness, temp?

Lighting?

Furniture, hides, plants?

I like the spotted gar and arowana choices, as long as they are of comparable size. These should grow at roughy similar rates and remain compatible indefinitely, meaning shouldn't prey on each other. Also, 400 gal would be good for them for 2-3 years, assuming average growth. RTC will need rehoming when it grows to be able to swallow its tank mates. Arowana and gar are easy to swallow, being of torpedo shape. Not so much oscar. So Oscar can be added to the mix too, I think, but I'd watch for aggression from the oscars.

In 3 years, or so, the tank will become too tight for the gars and arowana and would need to be increased at least by 2x. JMO. Many can and may disagree.

For the RTC, the tank will need to be upgraded in 1 year, assuming average growth. The RTC will be close to 2' by then and will have eaten all gars and arowana.
 
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lulumallick

Feeder Fish
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Nov 6, 2018
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So, what's your experience? What have you already kept and for how long and in what tanks / ponds? Or does your OP describe your entire experience of significance - two oscars to 10" in two 75 gal tanks?
Currently I have 4 tanks. 2X75 gallon 2 oscars raised from more than 1year and 1X30g palnted with 6 neon tetras, 1X10g planted with 4 tigers barbs. I m into this hobby for about 2years. I really love the oscars. I have learned to keep water quality stable.
Ok, 6'x3'x3' pond, 400 gal... As RD stated, describe the filtration and aeration, please, water change schedule, etc.
I am using external filtration which runs about 500g per hour. As i learned about monster fishes, I have to do 30-40% water changes weekly. Correct me if i am wrong.
Is it indoor or outdoor pond, what will be the pH, hardness, temp?
It is an outdoor pond. pH is 7, present temp is about 23-26C.
Lighting?

Furniture, hides, plants?
Will add lighting and driftwood for hiding. And some flowing plants like water lily.
 

thebiggerthebetter

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Currently I have 4 tanks. 2X75 gallon 2 oscars raised from more than 1year and 1X30g palnted with 6 neon tetras, 1X10g planted with 4 tigers barbs. I m into this hobby for about 2years. I really love the oscars. I have learned to keep water quality stable.
*****Sounds good. You should have some basics down. If you don't do it already, I'd recommend buying a water test kit. The liquid kind with test tubes. Not dip sticks. API freshwater master test kit is roughly $20 here in the US.

I am using external filtration which runs about 500g per hour.
*****Need more info on the filter size and media. 500 GPH will not do. You need at least 5 times an hour turnover rate, better 10. Which means at least 2,000 GPH pump, better 4,000. At these rates, you can get away without an additional aeration.

As i learned about monster fishes, I have to do 30-40% water changes weekly. Correct me if i am wrong.
*****It really depends on the bioload and how high nitrates would get. Initially even less could suffice. When fish will have grown, be prepared to possibly change more water, like 100%.

It is an outdoor pond. pH is 7, present temp is about 23-26C.
*****How are you going to handle yearly temperature seasons? Also, how will you handle algae? Overheating, if in the sun?

Will add lighting and driftwood for hiding. And some flowing plants like water lily.
*****For an outside pond, I'd not think you need lighting, just very dim night light would be beneficial. Catfish in general dislike strong light. Driftwood is good but also impairs your ability to observe the fish and uneaten food, if any, also takes away from swimming room, which will be more of a problem later on. Water lilies would provide the shaded areas but with the flow rates I recommended, they may not be possible to have.

*****I note you said nothing on the hardness. I think it'd be a good idea for you to learn to use the hardness liquid tests, both KH and GH. You will learn about your water and also it will enable you to be on guard against pH swings and pH crash.
 

thebiggerthebetter

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L lulumallick How is it going? Are the wheels spinning behind the curtain?
 

lulumallick

Feeder Fish
MFK Member
Nov 6, 2018
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How is it going? Are the wheels spinning behind the curtain?
Currently I have not stocked any fish yet. Reason:
1. planning to make an external filter which can run approximately 2000G/Hour. Got an pond thermometer to maintain water temperature.
Also water test kit to guard on water conditions.
2. after that for one month will add some walking catfish from local area to complete the nitrogen cycle and to check how fishes behave to the current setup.
3. after one month if everything goes well, will remove walking catfish and add juveniles of Spotted Gar, Peacock Bass and Silver Arowana.
No decorations and lighting, only floating plants.
 
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thebiggerthebetter

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Naples, FL, USA
Currently I have not stocked any fish yet. Reason:
1. planning to make an external filter which can run approximately 2000G/Hour. Got an pond thermometer to maintain water temperature.
Also water test kit to guard on water conditions.
2. after that for one month will add some walking catfish from local area to complete the nitrogen cycle and to check how fishes behave to the current setup.
3. after one month if everything goes well, will remove walking catfish and add juveniles of Spotted Gar, Peacock Bass and Silver Arowana.
No decorations and lighting, only floating plants.
Don't use wild fish for the cycling. They will introduce all kinds of pathogens into your setup - bacteria, virus, and parasites.

We still appear not know how big the filter is, what kind (you mentioned canister before?), and what the media is. Flow rate will not mean much if there is not enough beneficial bacteria settling the filter and if the water incoming to the filter is not aerated enough to sustain healthy bacteria populace.

But seeing how thorough you are with everything else, I am supposing that perhaps you don't need our input on the filter.
 

lulumallick

Feeder Fish
MFK Member
Nov 6, 2018
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Don't use wild fish for the cycling. They will introduce all kinds of pathogens into your setup - bacteria, virus, and parasites.
Ok, I won't add wild fishes. Which fish can I add for cycling ?
We still appear not know how big the filter is, what kind (you mentioned canister before?), and what the media is. Flow rate will not mean much if there is not enough beneficial bacteria settling the filter and if the water incoming to the filter is not aerated enough to sustain healthy bacteria populace.
I have to buy this type of submersible pump.
https://www.amazon.com/dp/B008FDJUN...4d-11e8-a8c6-1b706237d91c&smid=A1Y4RBJHD0SC34
I will put a 20Gallon (or may be more than that) bucket on the top-corner of
the tank. Will submerge the pump and connect the pump to the bucket and output the water to tank back. Filter media would be
sponge pad, ceramic rings, cotton pad.
Guide me if any other should be added. Really thanks for your advice.
 

thebiggerthebetter

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Dec 31, 2009
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Naples, FL, USA
Ok, I won't add wild fishes. Which fish can I add for cycling ?
*****People do it differently. My preference is fishless. I don't like knowingly causing discomfort to any fish. You can do it with an over the counter ammonia solution from your local farmacy (ammonium hydroxide solution) - dose it to get to a few ppm and at the same time you can play and learn well how to use a liquid test tube tests as you must test for ammonia, nitrite, and nitrate to keep track of the cycling development. Or you could throw in some fish food and let it rot and produce ammonia. Either way, I'd not let the ammonia to climb too high like 5-10 ppm because I've read recently that the BB that develop in high ammonia and low ammonia situations differ. If a bit impatient, get some commercially sold BBs or from another tank to seed yours. This may speed things up 2x-3x, from the usual 4-6 weeks. But your starting fish are tiny with respect to the tank and filter size, so you could be good in a few weeks anyway.


I have to buy this type of submersible pump.
https://www.amazon.com/dp/B008FDJUN...4d-11e8-a8c6-1b706237d91c&smid=A1Y4RBJHD0SC34
*****This is not a submersible pump, it's an above ground. Also, this is a bad choice in terms of performance (large head capacity, lower flow) and cost of electricity. Plus above ground are noisier. You can buy a 2500 GPH pump (which will output your needed ~2000 GPH at around 5' head pressure) that is submersible and consumes 3x less, only around 200 Watts of electricity, as opposed to the one you picked out that consumes ~600 W or 3/4 HP. Anyhow, I'd advise you to give Ted at PondUSA a call. He will pick and sell you the best pump and the best customer service there is IMHO and IME. I've enjoyed his help in buying ~$10,000 worth of submersible pumps over the years.


I will put a 20Gallon (or may be more than that) bucket on the top-corner of
the tank. Will submerge the pump and connect the pump to the bucket and output the water to tank back. Filter media would be sponge pad, ceramic rings, cotton pad.
Guide me if any other should be added. Really thanks for your advice.
*****Sounds ok. I'd probably go bigger but I stock too heavy for most people taste. Just make sure the water poured into the filter is well aerated and use a mechanical filtration mat (or an aquasock) on the top to lessen your having to clean the filter. It's not fun to clean a filter. DIY Aquasock example: https://www.monsterfishkeepers.com/...out-filter-socks-everyday.508202/#post6084230

I'd also recommend reading Darrel's input on filter types in this thread (dw1305): http://www.planetcatfish.com/forum/viewtopic.php?f=10&t=41716#p284597


Bottom line is: aeration is as important as the amount of biomedia. I'd probably go wet/dry filter in your case. This is the best.
 
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