Potentially beneficial bugs
In nature, creepy crawly critters are a hugely important part of the ecosystem, but in most homes they are violently rejected. This really seems like a missing piece of the puzzle-- I mean, obviously you can't very well re-create an entire functioning ecosystem inside your house, but...
Has anyone had experience with helpful critters in their growing media or areas-- particularly in hydroponic systems??
In hydroponic systems and other related moist conditions like wall gardens and terrariums, disease can spread super fast and wipe out a lot of plants. Most of the time you see people discussing ways to keep their systems pretty sterile-- but plants don't do sterile very well, they rely a lot on beneficial fungi, so the situation seems a bit backwards to me. Also, in a healthy system like a well-running aquarium, beneficial critters compete with nasty things, helping prevent disease.
I actively culture some live creepy crawlies to feed to the fish in my aquariums. I keep an aquatic compost tank, which breaks down scraps to supplement my main tank, where my aquatic plants are growing so fast they use up the nutrients faster than my fish produce them. I also use aquarium water to feed all of my houseplants and orchids, which I grow using the passive hydroponic method otherwise known as semi-hydro.
Some of the critters of interest:
SPRINGTAILS (Collembola):
Teeny tiny guys the size of the period at the end of this sentence. White or gray, they are often seen hopping about on the surface of water. Likely to be found in your humidity trays, they are extremely prolific everywhere in the world.
Recently I've been studying terrariums, and I keep seeing springtails mentioned as a very important clean-up crew that can not only serve as live food for pets such as dart frogs, but help control unwanted mold.
I just came across some interesting information from a study in which beet seedlings were exposed to springtails and pythium (the dreaded root rot fungus). Springtails alone caused some limited damage to the seedlings. Pythium alone destroyed the seedlings. But a combination of the two resulted in less damage than either alone-- the springtails would rather eat the pythium than the plants. That's awesome.
ASELLUS AQUATICUS:
The water hoglouse, an aquatic species of sowbug, is an isopod that feeds only on decaying matter (or perhaps just the fungi growing on it). They get to about half an inch long and trundle around on the bottom, where they like to dig in substrate. I have seen them mentioned as a potential way to keep fish eggs clean in breeding tanks, as they may eat away fungus and dead eggs while leaving the healthy ones alone. I haven't found a source for these yet-- Carolina Biological has some, but won't ship to California (despite them being native and ubiquitous... in theory I might be as to go outside and catch some). Seems to me these could be very cool in a hydroponic system, crawling about on roots and nibbling away any dead bits or mold.
SCUDS (Gammarus):
A quarter-inch long at their biggest, these amphipods look like tiny gray shrimp, with little gills constantly fanning under their curled tails. They sit or crawl about, but can also swim quite fast, zooming around randomly in smooth swooping motions. These make great fish food, but might chew on plants or predate on other critters like daphnia. Asellus are probably a safer option.
SEED SHRIMP:
These look like swimming sesame seeds, adorable little bubble-like copepods that swim in dizzy loops. They are filter feeders, with small fronds that pick up bacteria and the like. They live in pools that periodically dry out, so they can hatch from eggs that have been dry, but in aquaria I find their populations very unstable-- they may need the dry cycles to keep proliferating regularly.
DERO WORMS (Dero digitata, sometimes called microfex):
These get barely half an inch long max, white or pinkish in groups. They like to clump together under a protective layer of slime while they feed on tiny stuff like bacteria and protozoa-- and can help produce infusoria for culturing other critters like daphnia. When found drifting through the water, they swim with a distinctive corkscrew thrashing motion.
CALIFORNIA BLACKWORMS (Lumbriculus variegatus):
You can think of these as aquatic compost worms. Usually seen at 2" or so in culture, although they can grow larger. Contrary to popular belief, you do NOT have to store these in 1" of water in the fridge. They will thrive in the deep, warm water of an aquarium-- provided there is enough oxygen and food. They will eat just about any kind of scrap. If the oxygen levels are very high, you won't see much of them, but as soon as the levels drop a bit, you will see little tails sticking up out of the substrate into the water, up to an inch or so (with enough of them it can look like weird pink grass). Good treat for fish, without the diseases that tubifex worms can carry. They are native to North America and Europe (maybe Asia too?) and can be found in the muck all over.
NEMATODES and PLANERIA:
I've heard some of these can be pretty useful but I don't know much about them. They tend to turn up everywhere, at any rate.
SNAILS:
I am very curious whether snails can be used to help control algae in clear hydroponic pots. Anybody know of any snails that can climb far enough out of the water to work on that, without chewing on plants or roaming around the living room??
In water I am familiar with these types:
Malaysian trumpet snails will multiply to epidemic proportions in a tank with a lot of detritus, but in of themselves are harmless. They don't eat live plants, even if they're pretty hungry, and hide in the substrate most of the time, coming out at night to munch on algae and dead plant matter. They like to dig, BUT-- contrary to rumor, trumpet snails do not do much to aerate substrate, rarely burrowing much more than 1" down. Live bearing, they do not lay eggs. They have pointy cone-shaped shells, and a distinctive snout.
Ramshorn snails are more decorative, though they will chew on live plants if they are hungry enough. May be bright pink, red/orange, lavender, gray, brown, or black. Shell curls in a flat coil like a cinnamon roll.
Also commonly found in aquaria and other wet situations are pond snails-- the smaller, obnoxiously prolific Physa pond snail, about 1/4-1/2", and the larger (up to 2") Lymnaea pond snail, which can climb out of the water and breathe air if it needs to (maybe it's a candidate for hydroponic situations? I wonder!). Physa have long skinny eye stalks (unless fish nibble them off), while Lymnaea have short, triangular ones-- also if the snail is crawling on the glass, with the tip of the shell pointing upward, a Physa's shell will open to the left, and a Lymnaea's shell opens to the right. Both prefer dead stuff to eat but will probably chew live plants if hungry enough, like the ramshorn.
Most snails eat some algae, but nothing beats the algae-mowing power of the nerite snail, which can even eat black beard algae. Nerites eat algae ONLY, and may starve if there's not enough-- also they can only breed in salt water, and will tend to leave inert white eggs stuck everywhere in a freshwater tank.
If you have too many snails, predatory assassin snails can be used to help control them. These are not hermaphroditic like other snails, and must breed in pairs.
A side note-- snails and other shelled creatures (isopods, copepods, etc) need more calcium in the water than worms or springtails, and may not do so good in a low-pH environment.
I am very tempted to try an aquaponic system that actually incorporates aquatic compost in the reservoir itself, with asellus, worms, and maybe even snails. A pump and some bubbles would keep it nice and oxygenated, and the critters would help keep the filter clean, breaking down wastes into plant food.
The main issue I see with it, of course, is that it's a lot harder to figure out the actual nutrient balance of a DIY primordial soup, than it is to simply measure out and mix manufactured fertilizers in known amounts.
I'm very curious about your thoughts or experiences on all this!
Last edited by rosemadder; 12-27-2013 at 02:39 PM..
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