Recently I've gotten into a side hobby of culturing blackworms. I think blackworms have a lot of potential for a great and easy live food to culture but there isn't a lot of good information online on how to best take care of them. So I have been doing little experiments to try to learn more about their care.
I have found the blackworms do care a lot about water quality, sure they can tolerate slightly worse water than most fish but they won't thrive in it. In fact I've had a lot of die off when the water got too dirty. I keep high water quality in my cultures by connecting them to my other tanks. This can be done in many ways but what I do is use any plastic tub, a uniseal and PVC for an overflow. I connect it to my tanks flow using these fitting used for irrigation tubing, of course you could also use airlifts, or a small seperate pump.
Here is an example of one of the tubs on top of a 20G long tank
Here are my other culture containers.
As you can see I also glue some mesh around the overflow to reduce blackworms leaving the culture. I've found blackworms can still make their way through this mesh but it keeps down how many leave the culture. Even without the mesh the blackworms leaving the culture hasn't been too significant. But worms leaving the culture may be ideal for some as this could be automatic feeding.
I currently use a sand substrate as it is what I had on hand. I added some filter sponges to some of the cultures and the worms all go in the sponges completely ignoring the sand. In the cultures without the sponges and just sand only a few worms burrow, they mostly stay in clumps on top of the sand. Still learning about how useful it may be to use the sponges. For the most part they are only a hindrance, but the worms do really like them so I wonder if that may help the production of the culture. One thing they are nice for is keeping the worms concentrated where you want them, this can make feeding easier.
Since water quality isn't a huge concern in these I have been trying to push the limits on how much I can feed them. Here is about what I have been feeding this culture every day. Unfortunately I don't have a good idea on the mass of the worms in this culture, but on this day they were fed 10g of kens veggie flakes.
24 hours later.
As you can see they completely devoured all of those flakes. That amount of food would have crashed most culture setups I have seen which is why I think it is very important to overfilter with blackworms. Many guides I have seen suggest feeding small amounts two or three times a week. But they can clearly eat very significant amounts of food. However it may not be nessecary to feed that much depending on how much worm mass you are trying to yield. This is what I hope to find out.
Here you can see the green flake food inside the worms.
So far flakes have been their favorite food, which makes sense as they are very thin and easy to break down. I originally fed algae wafers which they also like but they are not able to go through them as fast as flakes and I want to maximize how much they can eat. I think ideally you would feed small amounts of flake throughout the day rather than the single big feed I am doing, but I haven't figured out an easy way to automate this. The problem is that it is best to place the food right around all the worm clumps which would be hard to to with an auto feeder, and flakes float. For now this is good enough though.
I have tried cutting up the worms with scissors before but I belive I found too much mortality for it to be worthwhile. There is also likely a lag period where the worms are healing and cannot eat as much which means less worm mass produced that day. So I am moving away from manual fragmentation for now and just seeing how much they will grow on their own.
Here is day one after manual fragmentation.
Day 3 I am starting to see more die off.
Day 7 I see significant die off. I think here I may have lost at least 50% of the worms.
Day 10 they seem to have stabilized. And decided to end this experiment after seeing this much die off. Perhaps the conditions were just not optimal for good healing, maybe too dirty, overcrowded, fed too early etc. I am not sure. I may try again in the future. I am open to suggestions.
My newest experiment just finding out exactly how much the blackworms can eat and how fast they can grow. I started with 15.15 g of worms. I will weigh them again in a week.
Unfortunately this experiment isn't perfect because the worms can leave through the overflow but I am hoping their reproduction is fast enough this won't be a significant factor. I started off with 500 mg of the kens veggie flakes. I forgot to take a picture of how much this looks like. But here is 24 hrs after feeding. As you can see only green waste is left.
Today I am trying 1g of veggie flakes I will soon update on their response to this much food.
I have found the blackworms do care a lot about water quality, sure they can tolerate slightly worse water than most fish but they won't thrive in it. In fact I've had a lot of die off when the water got too dirty. I keep high water quality in my cultures by connecting them to my other tanks. This can be done in many ways but what I do is use any plastic tub, a uniseal and PVC for an overflow. I connect it to my tanks flow using these fitting used for irrigation tubing, of course you could also use airlifts, or a small seperate pump.
Here is an example of one of the tubs on top of a 20G long tank
Here are my other culture containers.
As you can see I also glue some mesh around the overflow to reduce blackworms leaving the culture. I've found blackworms can still make their way through this mesh but it keeps down how many leave the culture. Even without the mesh the blackworms leaving the culture hasn't been too significant. But worms leaving the culture may be ideal for some as this could be automatic feeding.
I currently use a sand substrate as it is what I had on hand. I added some filter sponges to some of the cultures and the worms all go in the sponges completely ignoring the sand. In the cultures without the sponges and just sand only a few worms burrow, they mostly stay in clumps on top of the sand. Still learning about how useful it may be to use the sponges. For the most part they are only a hindrance, but the worms do really like them so I wonder if that may help the production of the culture. One thing they are nice for is keeping the worms concentrated where you want them, this can make feeding easier.
Since water quality isn't a huge concern in these I have been trying to push the limits on how much I can feed them. Here is about what I have been feeding this culture every day. Unfortunately I don't have a good idea on the mass of the worms in this culture, but on this day they were fed 10g of kens veggie flakes.
24 hours later.
As you can see they completely devoured all of those flakes. That amount of food would have crashed most culture setups I have seen which is why I think it is very important to overfilter with blackworms. Many guides I have seen suggest feeding small amounts two or three times a week. But they can clearly eat very significant amounts of food. However it may not be nessecary to feed that much depending on how much worm mass you are trying to yield. This is what I hope to find out.
Here you can see the green flake food inside the worms.
So far flakes have been their favorite food, which makes sense as they are very thin and easy to break down. I originally fed algae wafers which they also like but they are not able to go through them as fast as flakes and I want to maximize how much they can eat. I think ideally you would feed small amounts of flake throughout the day rather than the single big feed I am doing, but I haven't figured out an easy way to automate this. The problem is that it is best to place the food right around all the worm clumps which would be hard to to with an auto feeder, and flakes float. For now this is good enough though.
I have tried cutting up the worms with scissors before but I belive I found too much mortality for it to be worthwhile. There is also likely a lag period where the worms are healing and cannot eat as much which means less worm mass produced that day. So I am moving away from manual fragmentation for now and just seeing how much they will grow on their own.
Here is day one after manual fragmentation.
Day 3 I am starting to see more die off.
Day 7 I see significant die off. I think here I may have lost at least 50% of the worms.
Day 10 they seem to have stabilized. And decided to end this experiment after seeing this much die off. Perhaps the conditions were just not optimal for good healing, maybe too dirty, overcrowded, fed too early etc. I am not sure. I may try again in the future. I am open to suggestions.
My newest experiment just finding out exactly how much the blackworms can eat and how fast they can grow. I started with 15.15 g of worms. I will weigh them again in a week.
Unfortunately this experiment isn't perfect because the worms can leave through the overflow but I am hoping their reproduction is fast enough this won't be a significant factor. I started off with 500 mg of the kens veggie flakes. I forgot to take a picture of how much this looks like. But here is 24 hrs after feeding. As you can see only green waste is left.
Today I am trying 1g of veggie flakes I will soon update on their response to this much food.
