I have heard of adding rock dust, but I can't justify paying for anything that goes in the bin when the worms are perfectly happy with foods you can get for free. The rock dust is not for the worms, but for the soil.

I use eggshells ground up in a coffee grinder. It goes quick. Some add well crushed soil. Some add lime (not the fruit). My wife and kids eat a lot of eggs, so I have a decent supply of shells. I sprinkle it on top and sometimes add it to what I find to be particularly acidic foods.

I use rock dust, or i should say a mix of grit, silica sand sized to dust. But i get it for free. Its the kind of soil i have.

The worms need grit for their gizzards. I started adding the dust when i read a article (sorry i no longer have the article) on the web by a worm farmer who never added grit to his beds. He had been in the business for a few years. He had always maintained that adding grit was not really needed but to prove the point he added grit to one of his beds.

The result was the worms processed the bedding at a increased rate. He stated that the bed was easily distinguishable from the surrounding beds.

I found after i started using the rock dust the worms would work on paper far quicker not waiting until it was rotting first. I had been adding egg shells all along so i believe while they work the rock type grit works better.

african, how did your experiment with kelp turn out? What percentage of kelp to other feedstocks did you use? I will try about 50% kelp in my new bin and any advice would be appreciated.

There's a landscape soil ammendment named Ironite® that contains Calcium, Magnesium, Sulfur, Cobalt, Iron, Manganese, Molybdenum, and Zinc. Sold in 25 lb bags by various retailers, including the well known home improvement store chains. It's derived from Utah mining wastes. IMO it's an excellent example of recycling. However, the state of Maine doesn't agree, and they've blown Ironite's *trace* content of arsenic and lead wayyy out of proportion. Classic case of environmental hyper-alarmism.

If you prefer an organic source of concentrated minerals, there's Hollytone®, which contains Boron, Chlorine and Copper in addition to the minerals labeled for Ironite. However, it's quite acidic and thus is marketed for acid loving plants like hollies, rhodies, blueberries, etc.

Both products are granular.

I use both products at home but it never occurred to me to add a mineral supplement to my indoor worm composter. I really don't think it's necessary, and neither do the pro worm culturers. However, if you insist on supplementing you could pulverize a pinch of the Ironite OR a tsp of the Hollytone in a mortar-pestal and then sparsely sprinkle it in the bedding.

If grit will help at all, I wonder if a pinch of kitty litter would do the trick. It is clay and therefore has a very small grit size.

I wonder if the grit that is used for pet birds would work or if it would be too big?

I add about a tablespoon of fine sand every 2-3 months for grit because they need it for their gizzards. I wouldn't worry about minerals; they get plenty from the vegetable scraps.

Yes worms have gizzards. Do said worms need sand or grit or ground up shell? Please research because as far as is known Kelly said no. A gizzard does not a grit needing creature make. What say ye?

I recently added sand (for the first time), three handfuls. Within a week I noticed a huge amount of castings on top of the bedding that weren't there before.
I had originally bought the sand (at a builder's supply) for something else and since I didn't know the source (maybe beach sand), I washed it well before using -- to get out any possible salt content. I have a large rubbermaid-type bin and it always seems that no matter how much wet shredded cardboard I add (as bedding) the worms process it and there's always room for more.

Shaul

I add a teaspoon of garden lime to my worm everytime a feed them. I found the lime at a local lawn and garden store. It is basically calcium carbonate (pulverized limestone and shells). Whatever you do don't use anything that has calcium hydoxide, it will burn the worms.

Here is a link that might be useful: Worm4Earth.com

If they need microscopic grit, then kaolin could be what you would want. Kaolin is found in many types of clay, raw glaze, and the shiny coating on magazine pages.

Wouldn't that be odd if those shiny pages we are avoiding could actually have something they might be able to use to process faster?

Ironite OR a tsp of the Hollytone brand of products or kaolin, or greensand, etc. etc. etc. the reason I would have for adding these things would be so they are locked into the castings and thus available to the plants. Feeding the soil feeds the plants. That is the bedrock of organic farming. Maybe it should be for all farming.

I add rock dust (Azomite), leonardite, kelp meal, liquid kelp and greensand. A lot of fruits and vegetables are lacking in minerals. Rock dust adds minerals and feeds microbes which feeds the worms. Leonardite adds organic matter and humic acid. It feeds the beneficial microbes that feeds the worms and helps plants take up minerals other wise locked up. Kelp adds minerals and again feeds beneficial microbes and worms. Greensand adds iron and minerals. Yes all of this cost money, but all of my worms and plants have benefited greatly because of all of these amendments. My worms get feed a huge variety of other organic food and compost. I think sometimes my worms eat better than me. Our soils can be so depleted of minerals, it helps to put back what has been taken out. A healthy organic soil feed with worm manure will only release what nutrients and minerals the plants need.

Google some of this stuff and check it out. I believe its worth our good health, the health of the soil and the earth.

Here is a link that might be useful: rock dust and leonardite

"Wouldn't that be odd if those shiny pages we are avoiding could actually have something they might be able to use to process faster?" Yes.

Has anyone here tried experimenting with shiny paper? I know someone once put a cracker box, or something similiar, in their box and they said the worms ate the inside of the box but not the outside.

Well I put in a Wheaties box and a cracker box or two I never did find any part of these boxes but what do I know I just feed my worms whatever. I do use grit as sand or compost dirt. Charles Darwin found small stones in the digestive tract of the worms when he was studying their diets. Most likely he studied Lumbricus terrestris.

Curt

I'm not sure adding additional minerals is cost effective. Not if you have to buy them anyway. Sure, ironite and greensand will help plants. But I'm not sure feeding them to the worms is going to help them at all. The big advantage to using worms in the first place is their ability to take a large amount of substandard food and convert it into a smaller amount of high quality material to grow plants.

Excess material ingested is usually excreted anyway. That works when you are keeping all the waste. But my thinking is it might not help the worms at all. A group of animals that are malnourished will not prosper (grow and reproduce).

Sure, I know somebody will point out that worms tend to lay alot of cocoons if they are stressed. But that is a behavioral response to preserve the species- lay some eggs for when conditions improve. A tomato will blacken on the bottom and sacrifice part of the fruit in order to at least preserve some of its seeds. The species continues.

My point is you do NOT have to add alot of supplements to worm food to maintain a healthy colony and get the full benefit of microbial action in the castings. Extra stuff is just something you are adding to your garden. If it is needed by the plants, great, if not, you spent money you did not need to.