Grindal Worms

I recently started culturing grindal worms to feed to my Elassoma gilberti, gulf coast pygmy sunfish. For $12 I ordered a full colony of grindals off aquabid, which really impressed me price-wise because it included shipping. When the culture arrived, hundreds and hundreds of worms were all over the place, all up on the lid, all over the soil/stuff inside. I used two tablespoons of worms to start two synthetic substrate cultures (using scotch brite® pads and dollar store sponges). They're inside plastic shoe boxes with a centimeter of water on the bottom and the lid resting on the top of the box but with an inch of gap to let air in.
The main culture, after a minor die off from me stupidly watering them too much, still has lots of live worms in it, but it takes me a long time to dig through the substrate with tweezers and collect worms from it. (Their numbers still aren't high enough, after me killing them off with too much water, to crawl over the lid of the container like they did before). So I don't want to overharvest it so much that there aren't any worms left. Also, it takes like an hour and I just don't have that time every day to dig for worms.

Here's my question:
How do I harvest worms from the scotchbrite® pads and from the sponges of the synthetic substrate cultures? Online, people suggest to feed the culture and then in an hour or three to come back and collect the worms from the surface. But when I feed the worms, they just stick the tiniest little bit of their heads out of the sponges and don't come out enough for me to easily collect them. Does this just mean that there aren't enough of them yet? I read online that it took a few weeks for a culture to grow enough to be easily harvested, but it's been a few weeks and I've been feeding them every day with fish food pellets, and they're still not populous enough. Am I doing something wrong? Does it just take longer than this for them to breed? Should I expect them to be easily harvest-able in a few more weeks? Months? Do you all have any tips or tricks?

I've been thinking about it, and I'm going to drill regularly spaced holes into the lid. Maybe the one inch gap at the end of the shoe box lid isn't working, and they're not getting enough air. I happen to have a drill available for the next couple days, so I might as well.

I poke small holes in the lid and then stick a piece of foam in the hole to keep fruit flies and other pests out of my culture. I think you just need to give it time. My cultures are so prolific that I can scrape a layer fo worms right off the substrate at any time. I have a feeling we bought cultures from the same Aqubidder, Moses was their name I think. Great deal on grindals.

I poke small holes in the lid and then stick a piece of foam in the hole to keep fruit flies and other pests out of my culture. I think you just need to give it time. My cultures are so prolific that I can scrape a layer fo worms right off the substrate at any time. I have a feeling we bought cultures from the same Aqubidder, Moses was their name I think. Great deal on grindals.

Yeah, that's the seller. Those worms were a great buy. The culture was just teeming with life when it arrived, very awesome.

As regards to the foam, I definitely considered that. But I've got the two shoeboxes inside a drawer in a dresser, so there hasn't been any fruit fly contamination so far. The dresser is this little two foot wide, two foot deep dresser-thing that I bought to rest the standard 10 gallon guppy tank on. It had two drawers, so I stuck the grindal cultures in the bottom one. The advantage to that is that there's no way for fruit flies to get in, but now I'm wondering if they have enough air. My guess is that they probably do, because the first day I had them I left the shoe box lids on, and some of the worms suicided into the water, which I read they do if they don't have enough air. None of them are suiciding any more, so they ... probably? have enough air to survive. Maybe? I'll drill holes tonight just in case.

I think you're right, that they just haven't had enough time. How long did it take your cultures to grow up to that population density? Do the cultures ever crash, or do they keep going forever? Are you using a synthetic substrate like a scotchbrite® pad, or do you use soil? And what do you feed your worms and how often? I'm just curious what other people are doing that works for them.

Edited by EricaWieser, 13 September 2011 - 08:20 AM.

I haven't actually kept these myself so this is second hand, but I think I read somewhere that you can put a paper towel or similar on top of the substrate, and put the food on top of that. Then they need to go onto the paper towel to get the food and you can scrape them off more easily.

For mine (also purchased from Moses and a great deal as you mention), I took the clear plastic lid of a to-go container and cut it down to fit inside the Gladware. I just lay it right on top of the culture, and the worms congregate on it and stick to it when you lift it out of the culture. Depending on the tank I am feeding, I rinse the worms into another plastic container (from a frozen dinner - it's black so the worms show up very well in it) and feed using a dropper, or I just dunk the plastic lid thing in the tank I want to feed.

That book that came out a few years ago, Culturing Live Food for the Aquarium has pictures of the way I do it. If you consult that book, though, I find that the crewel work mesh he mentions is not really necessary, especially if you are doing the Scotch pad method.

Those are really good ideas! I could definitely do that

My culture seems to really take off if I use a yogurt covered piece of bread for food. It definitely takes time to build the colony up, I recall mine taking at least a week or so before I started harvesting them.

I didn't harvest any for a couple weeks. By the one month mark I had to harvest to keep the population in control. I feed mine multigrain baby cereal. I sprinkle it in a pile and give it a single spritz with a spray bottle full of tank water. My thought is that it's vitamin fortified so those vitamins transfer to my fish when they eat the worms. I culture microworms in a mix of oatmeal and baby cereal for the same reason.

Grindal worms are a great food and I have found them to be very easy to keep. I have had cultures going for about 2 years. I use top soil covered by milled sphagnum (to make them smell better and to refresh them every 6 months or so). That is just my choice for the substrate media and others have been successful using other methods.

To harvest I use a clear piece of plastic on top or the culture as you can see in the photos. I feed regular oatmeal and put 4 piles of it and then the plastic over the top. The piles keep the cover plastic slightly above the culture media. This keeps it from sticking.

Starting a new culture takes about 1 month to get it going. (Less if you start with more than just a few dozen worms) To do this you start with one piece of oatmeal. You add a couple more after the first piece has worms eating it. Remember in a new culture with top soil as the substrate there will be foodstuff in the soil so you might not see any action of the worms eating the oatmeal for the first few days. If you add too much oatmeal and the worms don’t eat it you will get mold, at that point, it is sometimes easier to start over. Every few days you add another piece or two of oatmeal. Once you start to see the worms on top of the media you start making 4 separate piles of oatmeal. Start small, as it will take a couple days for the worms to migrate to the new piles. At this time, you can add the plastic on top of the oatmeal.

To feed you just take the plastic and dip part of it into each tank that you want to feed. What could be easier?

To make sure that you have the right amount of moisture in the culture, make a trough on one side of the media. (See photo) The bottom of this trough should have just a little bit of water in it.

Harvest when you see enough worms on the plastic. Add more food every other time that you feed. Normally, I use each culture every 2-4 days depending on how it is producing. If you over use a culture you will drain it of breeding adults and will need to rebuild it which will take time.

I don’t use my cultures in the summer as they don’t produce well with the really warm weather. The photos are of my cultures, which I just started to feed again 2 weeks ago. If kept wet the worms will live for a really long time without any food.

Oh! There's some mold in my grindal worm culture! I had used dried oats to soak up some of the water when I overwatered them and some drowned. There were a lot of oats in there and not all got eaten, and some are molding a little. So that's why the culture isn't growing as quickly as I'd expected. That makes sense In the future, I'll make the trough design that you have so I can't overwater the soil-media worm culture. Thank you for the help!

Wow Thrifty!! You have ten cultures going. How many tanks are you feeding?

Jim Long who gave me my starter worms says kitten chow works best in his cultures. Jim grows LOTS of grindals in shoeboxes using upholstery foam on the bottom and pot scrubber pads on top. He keeps the boxes in a zippered pillowcase to keep out gnats and mites. I'm a newbie at grindals and not too successful yet, so I'll just relate what experts have told me.

I found that, when trying to get a new culture going, burying the food under the substrate a tiny bit really helped prevent mold. At the time, I was using ground coir, a little peat moss, and a touch of topsoil. This doesn't work as well if you are trying to harvest, but at the new culture stage it doesn't matter anyway.

When I started all of these I had 4 tanks with about 100 Rineloricaria sp Peru in each tank. They loved these worms and was the best way that I found to grow those fish. Right now I don't feed the worms as much and just dip them in any tank I have small fish or catfish in. However, with winter coming and with a lot of little cory catfish to breed I will be using them a lot more.

I bet that is great food but it just looks gross.


Usil

I found that, when trying to get a new culture going, burying the food under the substrate a tiny bit really helped prevent mold. At the time, I was using ground coir, a little peat moss, and a touch of topsoil. This doesn't work as well if you are trying to harvest, but at the new culture stage it doesn't matter anyway.

Awesome! Grindals do grow fish out well.

Sounds like you've never used them, Usil. Once you get used to using live foods, and see the health and growth benefits to your fish, a slimy wriggling mass of worms or a bucket full of mosquito larvae in gray-brown water becomes a thing of indescribable beauty. It's an attitude adjustment.

I bet that is great food but it just looks gross.


Usil

Sounds like you've never used them, Usil. Once you get used to using live foods, and see the health and growth benefits to your fish, a slimy wriggling mass of worms or a bucket full of mosquito larvae in gray-brown water becomes a thing of indescribable beauty. It's an attitude adjustment.

Especially after you see the happy look on your fish's face when you drop live worms in. It's like when a dog wags its tail and jumps up and down for a treat. The worms remind me of rawhide. Not gross, just not something I'd want to eat. Food that will make my pet happy.

Try the reptile coconut blocks. They will hydrate to 4 times their block size, and are Ph neutral. Cat chow, bread, and even fish food are great feeds, mix them up. When I wanted to harvest, I would use bread, and ultimately a writhing mass of worms would almost replace the volume of bread. I also placed small pieces of plexiglass over the feed.