Live food with fish?

[Jacob Hill-Legion Aquatics]

I was wondering Is it possible to keep a live food with fish in the tank so the fish have a constant food supply without the fish eating all of them and destroying the population?

if so what live foods would work?

[Theplatymaster]

@Jacob Hill-Legion Aquatics

 

possibly, depending on the type of fish.

if the idea is a snail culture, for pea puffers, if you add a very large amount to start it, and have lots of hiding spots for the snails it might work.

BBS can already be eliminated from this discussion it is saltwater.

Your tank already produces plenty of little infusorians and you might be able to get away with something like copepods that are small.

@modified lunghas good experience with live foods, can you help us out here?

[Jacob Hill-Legion Aquatics]

On 2/28/2023 at 3:19 PM, Theplatymaster said:

@Jacob Hill-Legion Aquatics

 

possibly, depending on the type of fish.

if the idea is a snail culture, for pea puffers, if you add a very large amount to start it, and have lots of hiding spots for the snails it might work.

BBS can already be eliminated from this discussion it is saltwater.

Your tank already produces plenty of little infusorians and you might be able to get away with something like copepods that are small.

@modified lunghas good experience with live foods, can you help us out here?

Yeah the idea would be to have a culture of cyclops or something in the tank.

im not 100% sure but I think saltwater guys do this kind of thing in reef tanks 

[Theplatymaster]

On 2/28/2023 at 5:36 PM, Jacob Hill-Legion Aquatics said:

Yeah the idea would be to have a culture of cyclops or something in the tank.

i think if you chose small fish, with small stomachs, like chili rasboras it might work, but try a zebra danios, and they will decimate the entire culture before you can say "cyclops culture".

so as i said, depends on the type of fish, definetly in this case (might not be possible) add the culture before the fish to get it established well before it is predated on.

[Odd Duck]

I tried this with pea puffers with 3 different species of snails, scuds, blackworms, and Daphnia all added about 12 weeks ahead of adding the fish, and still had to supplement with other live foods to keep ahead of them.  I’ve also tried with scuds, Daphnia, and blackworms with assorted other tanks and other species, but they always need more supplementing, even with sand substrate.

If you had a large enough refugium, super dense plants, and few enough, very small fish you might get there, but not terribly likely, IMO, especially if you’re trying to provide a good variety of live foods.  I have had populations of scuds stand up to a minimal density of very small predatory fish if they were well established before the fish went in (definitely not with the pea puffers even when I provided the scuds with custom refugiums in the tank) but not with Daphnia or blackworms.

I have been very surprised that I still have a decent number of blackworms in a sand bottomed tank with bristlenose plecos growing out in the tank.

[Guppysnail]

What type of fish?  
I have a couple types of fish that only eat live foods. For mine I seed my tanks with seed shrimp, scuds and neocaridina. The trick for mine is to start with food numbers too high for them to eat them all so they continue to reproduce faster than they are eaten. When possible I start the tank with food sources and let their population take hold before adding fish so I don’t have to have so many up front. 
For larger more aggressive fish I don’t think this would work. 

[modified lung]

Hundreds of scuds can live in an ACO coarse sponge filter. Every so often a couple will dart out into the open. For a year or two I had about 8 rosey red minnows in a 20 long that were only fed this way.

[tolstoy21]

Black worms can work if you put enough into the tank that they make it to the substrate.  I feed black worms and even when I haven't put any in tank in a while, I still find them here or there. 

Eventually, they fish will probably get them all, but they can last a decent amount of time. 

Of course, don't put so many in the aquarium that their waste fouls the water.

[Darax]

I have a feeling I could keep my goldfish alive on guppies if I replenished the stock from time to time. 

[Phoenixfishroom]

I have a stable neocaridina and/or scuds population in most of my tanks and daphnia colonies in the pipefish tanks. The first two work anywhere with the right parameters, lots of small hiding places, and enough live plants/moss. A warning though, if you don’t have enough fish to keep them in check scuds can get pretty out of control and when their population gets too high they will start damaging plants and can collapse an shrimp population in the same tank. Daphnia is more difficult to establish and will only work in a tank with really heavy planting and no filtration. You also need to dump kind of a lot in at the beginning and add more from time to time until the are able to establish themselves and I am not sure that they could ever get a real foothold in a tank with a heavy fish population or fast more agile swimmers…. It isn’t that hard to outrun a pipefish.

Edited March 7 by Phoenixfishroom
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[Phoenixfishroom]

Probably worth mentioning that I do still feed all of my tanks with flakes/pellets, wafers, frozen brine and mysis, and live insect larvae and flightless flies that I culture separately. It is quite possible that if it was the only food source feeder animals could not effectively populate tanks with micropredators.

[TOtrees]

On 2/28/2023 at 5:09 PM, Jacob Hill-Legion Aquatics said:

I was wondering Is it possible to keep a live food with fish in the tank so the fish have a constant food supply without the fish eating all of them and destroying the population?

As an ecologist by training (oh so many many years ago), this is a predatory-prey question. In nature, predators and prey can exist in balance with one another, but there are some major differences between "in nature" and our aquariums. 

- In nature, there are many many factors other than the predator or prey that will affect their abundance. These elements act like buffers to prevent either the predator or prey from leaning too hard on the other. 

- In nature, when a prey population drops too low, the predator population also falls. This allows the prey to recover. If your predator population is unchanging (or always growing), this won't happen. 

- In nature, immigration or emigration of the predator or the prey can also adjust their populations as each climbs and falls. Too many predators? Some will leave. Few predators? More prey may come in. 

None of this self-regulation can occur in a small closed system like an aquarium. With trial and error, a couple male guppies or platys in a 40+ gallon, with no filter, lots of light, and dosing liquid ferts (to fuel growth of green water algea and thus support a robust/booming daphnia population) might work. But, I don't see this hypothetical setup being all that nice to look at or enjoy.