Using Worm Castings in Hydroponics

I've been using vermicastings (i.e. castings from worms) in my deep water culture bubbler system for a couple of weeks. The 2 lbs of castings are stored in a paint strainer bag and submerged in 9 gallons of water. The castings are generated by 1 lb of European Nightcrawler worms that compost my kitchen scraps and a large amount of coconut coir used as bedding material. The "bubbling" comes from aquarium air stones and an inexpensive aquarium air pump that aerates the water.

Today while removing the old castings and replacing them with fresh ones, I noticed something very interesting and somewhat surprising. Live worms! I counted 5 or 6 without really looking too hard. The worms weren't just living in the top of the castings, but there were several submerged deeply under water.

I've been keeping worms for 3 years.  Based on my experience, too much water in a worm bin is not healthy for the inhabitants.  When things get too wet in the worm bin, I often find "drowned" worms.  It's rare that I get that kind of water in my bins these days, but as a worm keeping newby it happened more often when I would overfeed them.

I can only guess that the worms were able to survive in the deep water culture bins because of the aeration being provided by the air pump. If worms can survive in that environment, then the plants must like it even more than I thought. :-)

European Nightcrawlers vs. Red Wigglers for Home Composting

Eisenia foetida

I have been composting with worms for almost 3 years in my home.  I started with 1 lb of eisenia foetida and in a two year period I grew that amount to more than 19 lbs. I supplemented my composting efforts with rabbit manure purchased locally from a rabbit farmer to help multiply my worm population faster. If you have lots of worms you also need lots of food for them :-)

After our move from Florida to Michigan, I started my worm composting efforts over from scratch with 1 lb. of eisenia hortensis worms.  If you have never compared the two worms up close here's a quick description based on my experience and observations.

EF's

• 2-3 inches long
• small and skinny worm
• eat almost anything
• tendancy to ball up and group together in the bedding
• multiply quickly, 1 lb can double in size within a couple of months
• will compost and reproduce well in temperatures up to 100 degrees air temperature
• lots of room for error in bedding, they will tolerate poor bedding conditions for short periods of time
• commercially viable for vermicomposting ventures

EH's

• 5-6 inches long (even longer when extended)
• fatter worm than EF's
• a very active worm compared to EF's
• do not multiply as quickly as EF's, 1 lb can double in size in 5 or 6 months
• tendancy to roam and will escape if conditions do not suit them
• favor cooler temperatures
• favor lots of neutral material in their bedding
• do not like bedding that heats up
• do not like bedding that is too wet
• appear to do well in paper and cardboard bedding with small amounts of food material
• commerically viable for retail and wholesale sales as a fishing worm
• less desireable for vermicomposting and home composting, but acceptable

I have no plans to switch back to eisenia foetida for my home composting efforts, but if I do decide to get back into the business of selling worms to other home composting enthusiasts on a small scale I will add EF's back into the equation.