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Culturing Live Foods

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If you have ever fed your fish wriggling live foods, you will know that they love them much more than flakes or pellets. For most fish it’s a more natural way for them to feed. For many wild-caught fish or newly-hatched fry, it’s essential to feed live foods, at least until they can be weaned onto prepared foods. But live foods can be expensive and not all fish shops sell them. At some times of year availability can be a problem.
The solution is to maintain your own cultures of live foods. In this thread I’ll explain how I keep some of the easily-maintained wrigglers.
Feel free to add your own methods to the thread, but please don’t use it for discussion or questions – start a new thread and we’ll update this sticky if needed.

Daphnia are water-fleas. They swim around with jerky movements that are irresistible to most fish, which will gobble them up. Ideal for feeding tetras and other small mid-water swimmers, and bottom-feeders like Corydoras will go after them too. However, they’re too big for feeding fry.
They’re one of the easiest critters to culture, best done outside and requiring minimal maintenance. This may make them more acceptable to the other half, when compared to a box of worms in the house...
You’ll get a steady supply in summer, but in winter they stop reproducing and may die off in sub-zero temperatures. Mine did survive through the winter, briefly under ice, but I added a fresh lot from the LFS too.

After using an ordinary bucket last year, I have replaced it with two long plastic planters from B&Q, with the sides supported by some loose bricks.

There's a couple of inches of well-rotted horse manure in the bottom of each, topped up with tank water and a few live daphnia from the LFS. They're in the sunniest place in my garden.

Then, the care required is simply to leave them alone. Rain replenishes the water from time to time, while pigeons replenish the organic nutrients. Especially in sunny weather, the Dapnhia multiply into swarms.

To harvest, I take a small fine net, insert vertically at one end of the trough so it is entirely below the surface but above the manure, then sweep the length of the trough and lift vertically out. That process minimises any contamination from floating or sinking debris. I then give the daphnia in the net a good rinse under the tap, and feed to the tanks with my fingers or by swishing the net in the tank.

Sometimes you do get other bugs in with the daphnia. My fish seem to gobble them all up indiscrimanately :)

Microworms are tiny worms, about 2-3mm long. They’re a great first food for fry of bottom-dwelling carnivorous species such as Corydoras and dwarf cichlids. But even the adults of these species will enjoy them as a snack. They tend to be less useful for mid-water dwelling adult fish.
These are really easy to culture, but take a bit more preparation and maintenance than Daphnia.
Start with a plastic box with a well-fitting lid. I use the clear boxes from Indian or Chinese takeaways, that have a capacity of about 0.5 to 1 litres. Make some small holes in the lid, or alternatively cut a larger hole and stick some net curtain or other fine mesh across the hole. The idea is to allow fresh air in and out, but to prevent flies getting in.
Now put a layer of dry porridge oats in the bottom of the box – you want it about 1cm thick. Pour in some boiling water and mix to a sticky consistency. Let it cool – it should be moist and squidgy but not runny – you can add a little more water if needed.
Now add a dollop of starter culture (order this online for a couple of quid). Put the lid on, put the box somewhere safe and leave it a few days. I keep my microworm cultures on a windowsill in the light.
You will soon find that the worms multiply and start swarming up the sides of the box forming strange patterns. I use a small (craft) paintbrush, slightly moistened, to collect them off the plastic. Then I just swish the brush in the tank and the worms will swim free.
After a couple of weeks the box will start to smell a bit. This is your cue to start another culture. Just make a second one the same, but this time your starter culture is a dollop from the existing box. This can be continued indefinitely.
Banana worms are similar to microworms and can be kept in the same way.
Be careful to keep the worm cultures away from the kitchen, and wash your hands thoroughly...

 Grindal Worms
Grindal worms are bigger than microworms but significantly smaller than bloodworms: they’re white, about 5-10mm long and 0.3mm thick. They’re a great food for juveniles and smaller adult carnivorous species.
These are a little more effort than microworms or daphnia, but still pretty easy. Some people keep these in a soil-based culture but I prefer the soil-less method which is cleaner and is less prone to infestation with mites (well, it hasn’t happened to me anyway).
As with the microworms, start with a plastic box with a well-fitting lid. You can use a takeaway box but for the grindals I prefer a clip-lock box from the supermarket. Make some small holes in the lid. These worms will be kept in the dark so there’s less need to protect them from flies etc.
Now get some dark green scouring pads (‘scotchbrite’ or the cheaper own-brand alternative) and cut them to be a reasonably good fit in the plastic box. You want about 3 or 4 layers.
Get yourself a water spray-bottle and fill it with conditioned water (I just take this from my HMA filter but you can use whatever you use in your tank for water-changes). Spray the scouring pads until they are damp, and you’ve got just a thin layer of water on the bottom of the box.
Add your worms (cultures available online – you may end up with a bit of soil as well but don’t worry too much about that).
You will need to feed the worms. I use a variety of pelletised fish food that’s either going out of date or that the fish don’t like. The most productive I have found so far is Hikari baby cichlid pellets, but the worms aren’t too fussy. Start by putting just a little food on, and then spray it with some more water to soften it. You want all the food to be eaten in about 2 days – you’ll soon learn how much to add.
The worms will gather around the food, eat and multiply. Keep them in the dark as they’re afraid of the light.
I place a small piece of clear plastic on top of the food. The best sort seems to be the twin-walled cellular stuff used for envelope stiffeners etc, as the worms like to crawl into the hollow parts. Some of the worms will swarm over this (when left in peace in the dark for a couple of hours). When you want to harvest the worms, take the box out of its dark place, remove the lid, pick up the piece of plastic (I use tweezers) and just waft it in the tank water. Then add some more food to the box, spray with water again and put the plastic back in, the lid back on and put it back in the dark.
Another way of harvesting the worms is to scrape them off the top of the scouring pad with a spatula or item of cutlery (preferably one that won’t find its way back to the kitchen!). You tend only to get one go at this before they burrow back into the scouring pads, so it’s not as productive.
After about 2 weeks, they will start to smell. Take the box outside and drain off the water and waste accumulated in the bottom (this stinks). Dampen again with more water spray, feed again and carry on indefinitely.
If the food starts to go slimy or rot, remove it, and feed less next time.
Be careful to keep the worm cultures away from the kitchen, and wash your hands thoroughly.

 Baby Brine Shrimp
These require a little more ‘infrastructure’ than the worms, but are still quite low-maintenance and have the advantage that you can re-start the culture from eggs at any time. They also have a high production rate, and don’t require feeding.
BBS are a great first food for many fry, they’re tiny but they swim around in mid water in a way that attracts young fish to feed. It is possible to raise the BBS into adult brine shrimp, but to do this you need a different setup and you need to feed them (which is much more involved). The method described here is just for hatching the BBS.
The clue’s in the name, these need to be cultured in brine. A saltwater mix can be made up using marine salts from your local fish shop; I’ve also had success using un-processed ‘sea salt’ from the supermarket. Probably best to avoid normal table salt. You need to make a brine solution with about 5 teaspoons of salt per litre of water.

You can buy BBS hatcheries but I made my own. I made a wooden stand to support two 2L plastic pop bottles upside-down. Cut the bottoms of the bottles; these can be used as lids upside-down.
I bought some special bottle tops online; these have two pipe fittings going through the bottle cap and I think they’re intended for DIY CO2 setups etc. They’re quite cheap and much more robust and leak-proof than home-made options.
The two pipe fittings each need a length of standard airline fitted to them. One is to feed in an air supply to keep the water aerated and circulated – this should go through a control valve and a non-return valve to a small air pump. The other is a drain pipe for when you harvest the BBS – this just needs a clamp, bung or valve to close it off. I found that the normal types of airline valves gave a very slow drain rate and that a clamp or bung was a better option.
Close both the valves in the pipe. Fill the upturned bottle with the brine solution. Add a pinch of Brine shrimp eggs. Turn on the air and adjust the valve to give a gentle stream of bubbles. Leave for 24-36 hours.
When you can see the little BBS swimming around, it’s time to harvest them. Turn off the air, and drain the entire bottle through the drain pipe into a jug (make sure it’s big enough!). Then get a brine shrimp sieve (did I forget to tell you to buy one of these?) and pour the water from the jug, through the sieve, back into the bottle. The BBS will be caught in the sieve. Give them a good rinse through with fresh (not salt) water and then waft the sieve in the fish tank to set them swimming.
Now add another pinch of eggs to the bottle and turn the air back on to make another batch for tomorrow J.
I usually throw the water away after a few weeks and make a fresh batch. Don’t worry if it starts to go a little green with algae.


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