The experimentation with the coffee grounds has to a large extent, had a positive impact. Thanks to Bevan Dinwoodie of State 5 Coffee trailer for his support of the prototype and the readily available supply of coffee dregs.
The benefit of having an additional reliable food source which provides a relatively unchanged PH final product, is somewhat offset by the coffee grounds being small enough to be washed through the drainage holes resulting in a thick sludge rather than a more viscous worm wee. In order for us to successfully feed the wormwee into a mixer where it is mixed with water, then fed into the drip irrigation system , a filter system will be required. At this stage the mechanical filter that is at the end of the line fed by all the individual tanks, will require almost continuous cleaning. Thus a filter system within each worm farm is required.
The initial plan is to add a layer of geotextile fibre material which should allow the wormwee through without the bigger particles of coffee. Thus the liquid leaving the lower tanks should the already have been filtered to a greater degree and the last mechanical filter should then have a longer period between cleaning?
The wormwee having been filtered twice and collected in a larger sump, will then be pumped up into a reservoir where it will be mixed with water. Two float switches will regulate the amount of wormwee pumped into container A and this will be matched with a similar mechanism in container B. A manually operated solenoid will then be opened to allow equal amounts of A & B to be released into the drip irrigation system. In theory the “dreaded sludge effect “ will have been effectively dealt with.