nomadofthehills;1381822; said:
Sounds interesting, my ecology professor last semester was a mycologist, specializing in mycorrizal fungi.
How do you plan on encouraging this growth, and how do you know you have some?
I'm going to meander through this one for a bit to give some perspective to how my thinking has developed.
A number of years ago I had an assignment to increase the productivity of some stamping presses used to make coins, that had been in service for nearly thirty years and were of a design that was at least 50 years old. They coined at an average rate of 135 pieces per minute (the rate depended on the diameter of the coin and the alloy used). These machines were at the wrong end of the 'bathtub curve' and as a result subject to frequent stoppages and costly to maintain.
These machines by the nature of the work they do create a lot of metal dust. Coining is essentially a forging operation. Metal dust mixed with lubricating oil becomes a honing fluid and within a short period of time, pins and bushings begin to wear; causing backlash, unwanted vibration, tooling wear, timing problems, and a host of other issues that affect productivity.
The short term solution was obviously to increase the frequency of oil changes and include some inline mechanical filtration in order to keep the abrassive quality of the lubricating oil below an acceptable threshold, but this has an added labour and material cost that any good engineer feels obligated to reduce. (This is what we do when we include mechanical filtration for our aquaria)
After some research and collaborative design the solution was to provide a parallel, lower volume micro filtration for the oil sump, to remove the very small metal particles that blow through and damage the larger particle filter elements. This improved the effective service life of the lubricating oil and the larger partical mechanical filter element. The oil was monitored and subjected to detailed analysis by a third party tribologist and elements and fluid only replaced when parameters indicated it was time.
At the end of the project, the frequency of oil changes was reduced by 90% with a dramatic improvement in the life of pins and bushings. Press maintenance costs went from an average of $85k to $2k per year and available equipment time increased by 8% or 1 month per year!
The real benefit to this particular project apart from the productivity increase was the move away from simply following an equipment maintenance schedule that required oil changes based on a calendar driven schedule, towards a reliability based aproach that included monitoring the condition of the oil and changing it as it aproached certain parameters, minimising waste. When manufacturing equipment is set-up and running well, you don't as a rule want to stop it for maintenance-doing so introduces a whole new set of stresses on the system that can take days or weeks to eleiminate.
This brings me back to filtering fishtanks and mycorrhizal fungi. Most of us follow a similar pattern in maintaining our water quality. We use rudimentary bio/mechanical systems ranging from sponge filters to wet/dry filters that essentially remove most of the detritus and biological oxygen demand from our closed systems. The end product we concern ourselves with is usually nitrate, and when that reaches a certain level we conduct a water change to lower the concentration to between 50% to 75% of what it was.
The vast majority of us don't measure the nitrate level with any regularity or precision and simply follow a daily/weekly/monthly schedule anyway. This begs the questions; is there a
real benefit to changing water on a regular basis? how much wasted effort and energy are we putting in to this activity? what is the
real benefit to fish? what systems in nature complete the nitrogen cycle to reduce nitrates to
acceptable levels?
Does anyone have an
'Old Growth' fishtank that has a complete and complex community of organisms that 'auto-regulate' chemical parameters?
Nomad, in finally getting round to answering your question, I don't absolutely know how much of what type of fungi lurks in the substrate of my tanks. Getting back to my coining press analogy, my instincts tell me that having a parallel low-flow through system; a living filtration system that includes mycorrhizal fungi, will increase the rate at which all nutrients including nitrates are removed from the water column and reduce the need for water changes.
Rather than encourage growth in the tank substrate, I plan on setting up a sump with a course gravel filter on the bottom, covered with a geotextile fabric. On top of that, a transplanted piece of forest floor from the riparian zone that runs along the river that provides our municipal drinking water. Hopefully this will be complete with the fungi, bacteria, and plant life needed to extract, share, and remove the nutrient load that goes in to my system as fish food every day. I impatiently wait for Spring to find the right piece of dirt.
My thinking leads me to believe that at even at as low as 5 gph an equilibrium below acceptable concentration levels in nitrates, phosphates,etc, is acheivable, but this needs to be tested to be verified.
The system will require lighting and may pose a problem in that there are all kinds of insects and microworms that play an important role that will need to be controlled. Perhaps Fiddler crabs are the answer...or a vent to the outside of the building...I would apreciate any input and insite that others have on this subject.
