Appropriate Technology - Solar passive compost tea aeration unit

We are building a prototype for a solar passive compost tea aeration unit and are in need of advice on a suitable DC solar power supply.

The Idea :
Is a simple and cheap DIY system for farmers to make directly on site and then make their own organic bio active fertilizer from vermicomposted waste.
The compost tea can then be fed constantly at low dose and directly into the root zones, via dripline fertigation or foliar application.

The Aim :
To make quantities  (1000L batch) of bio active compost tea to feed directly into our dripline irrigation system (fertigation) - and excess for sale.
This unit is stage II of the vermicompost - worm farm system that we have existing. 

http://futurefeeders.weebly.com/our-blog/a-wriggling-resource
https://www.youtube.com/watch?v=eQgrNtbYXTw

The Design :
The aim to keep materials cost to a minimum to make the unit functionally affordable for small scale farmers.
As such we are aiming for under $1000. 

Request :
I am requesting some advice, availability and a quote for the most affordable appropriate stand alone solar system.  
The system will require sufficient stored DC energy to power the pump unit as below or similar for 48H.  Battery units will need to be able to maintain continuous operation, however w can assume viability under full sun conditions only.

Costs and Components :
<$100        Aeration Tank : Up-cycled 1000L holding tanks, readily available
<$100        Pump : Hailea ACO-007 DC 12V Air Pump or similar
<$200        Venturi Siphon kit   for variable control of soluble and liquid fertilizer injection
<$500        Solar panels and battery units
<$100        Sundries : air pipes, grommets, taps, wires etc

Pump Unit :
Hailea ACO-007 DC 12V Air Pump
POWER: 130W
OUTPUT: 140L/min
VOLTAGE: 12V DC
PRESSURE: >0.10Mpa


Additional Details :
The brews can be adapted to be more fungal / bacterial dominant and mineral enhanced depending on the requirements of the crop and soil type.   Soil Food Web has done great research on this.

There are a number of units like this on the market however this units point of difference is that it is low lech and low cost.  Big price tags and technicalities just put farmers off.
I am trying to develop an appropriate technology; somethings that just makes sense and is simple and get people using them.
These system could easily be adapted for remote communities, developing nations etc

There are 240V systems available, but there is a need for an 'in the field' design that is off grid.

Compost tea applications through fertigition have the potential to have big impacts on soil health, food nutrient density and plant disease resistance.  It also give farmers the ability create their own organic inputs and drastically reduce fertilizer costs while cycling nutrients through waste organic matter.

Would really value your input, assistance and support on this project.

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