What fish work well together?

[jpcw]

I'm moving up to a large tank (40,000L). What combination of fish work well together? I have a solar heater so can probably keep the water reasonable warm through the winter (Perth). Alternatively I could start with a cold water variety like trout and change over

[GaryD]

Hi John,

Can you provide more detail? Is your new tank actually a swimming pool?

How much space do you have around the proposed tank.

If you provide me with more information, I can probably provide some ideas that are better targeted to what you have in mind.

GaryD

[Dufflight]

I have silvers, catfish and goldfish in 55000ltrs and they go well together. Problem with larger tanks is the bio load and processing the water volume. Catching the fish is another story. Do you plan to harvest the entire fish load or just top up. Putting fingerlings in with trout or barra and cod may be a problem if they are close to mouth size.:D

[jpcw]

Hi and thanks Gary, Yes it is a swimming pool.

Space on one side of the pool is around 200-300sqm

Pool is kidney shaped and 4m x 9m width a depth of 2.1 at one end and 1m at the other.

I have a large shade sail over the pool that has been taken down for winter. This will probably cast too much shadow over the GB's but might be useful in summer

I have attached a very rough plan of the area. And yes the scale is completely wrong, the pool is not bigger than the back yard :)

Funds are going to be one of the biggest issues so I will have to work up in stages or on the cheap.

[jpcw]

Hi Dufflight,
Was going to try and catch as I go. The thought was to use the existing 1000L tank as a grow out tank.

I like the idea of Catfish, one of the biggest problems I will have is being in WA and most of the good looking fish being over east. I'm waiting for a call back from fisheries about the procedure for translating fish for a non commercial setup.

[Dufflight]

Bigger water = bigger fish. Something about growing to there enviroment. I use a smaller tank to get the fingerlings to size then put them in to the bigger tank. Are you going with 1 large gb or smaller ones. I like ready made gb's.

[jpcw]

Bigger water = bigger fish. Something about growing to there enviroment. I use a smaller tank to get the fingerlings to size then put them in to the bigger tank. Are you going with 1 large gb or smaller ones. I like ready made gb's.

Probably going with a number of smaller ones. Mainly so that I can add as I go. I'd imagine a single grow bed for a 40,000l tank wouldn't be cheap.

My initial thought was to get 50 – 100 of each type of fish to start and a smaller number of GB's and then expand a few months later. Pending any advice to the contrary that is.

Still trying to decide exactly what the GB's will be made of, might get a few largish pre-made, might make my own, might scrounge whatever material I can find etc. Probably will not go with barrels cut in half as I did with my 1000L setup, too many and too much mucking around.

[Dufflight]

I ditched the half barrels and went with larger gb's. Still like having a few half drums as duckweed grow space.

[GaryD]

Hi,


Bigger water = bigger fish.
In some situations, this seems to be the case (eg....silver perch) but with other species it doesn't seem to apply.

Even with silver perch it can vary. I had been told by experienced aquaculturists that silver perch (which can grow to quite large fish in ponds) would often not grow past about 350 grams in tanks. Recently, I came across a well-stocked tank (around 200 fish in 2000 litres of water) where many of the silver perch were approaching 800 grams.

We're starting to discover (from our interaction with some of the hatchery operators) that there are different strains of some species that behave quite differently from one strain to another. A prominent example is the golden perch which (in most strains) appears to be very difficult to wean onto pelleted food. The Lake Eyre strain appears to be much easier in this respect.

I think we're only scratching the surface in our understanding of what's really possible with some of our native fish.

GaryD

[jpcw]

How well would a few Marron go in the pool with a combination of catfish, silver or golden perch?

[GaryD]

Hi John,

It all depends on what you mean when you say "How would a few marron go.....?"

From the golden perch' perspective it would be great, they love to eat crustaceans....and so do most other fish. From your perspective, it might be less enjoyable.

Crustaceans must shed their shell to grow and, in the process, they become vulnerable to other organisms that like crustaceans.

GaryD

[jpcw]

Ok point taken. I may look at partitioning off part of the pool plus giving them plenty of places to hide.

[Dufflight]

Bread and Milk crates work well.

[jpcw]

Bread and Milk crates work well.

That sounds like a great idea, I was planning on sticking together some PVC pipes in a honeycomb arrangement but that sounds a lot simpler.

[GaryD]

Hi,

Nylon onion sacks or nylon bird netting also make good vertical habitat for crustaceans.....and help to separate them from other hungry organisms.

Garyd

[jpcw]

Hi,

Nylon onion sacks or nylon bird netting also make good vertical habitat for crustaceans.....and help to separate them from other hungry organisms.

Garyd

Ok cool, so I take it they don't get all tangled up in it then.

Looks like it might be a couple of months before the fish I want are available so I'll put the marron in the pool by themselves for now and work on their enclosure. Hopefully it won't be too hard to round them all up.