Frequently Asked Questions

What is an OnZite Wormfarm Waste System?

It is a gravity fed tank which processes all sewerage (black water), grey water and organic matter using worms.

What does the system look like?

Normally the 3,200 litre tank is below ground. On top you see a compost bin for garbage disposal and a 100mm vent pipe which protrudes approximately 3 metres. There is a distribution box where the trenches start so you can manage the flow of liquids to various trenches benefiting your garden.

Is the system approved?

Yes. VIC: EPA CA 81/14

NSW: Ref WCT 026

SA: Dept of Health WCS 01473

Will my Council allow me to install this system in my area?

Yes. However, on some sites extra design work may be required to meet local environmental issues.

Does the system require a lot of maintenance?

No. Virtually no maintenance, the system is designed to be self cleaning.

What does the system cost to run?

There is no cost as there is no power use plus there is no service contract with an OnZite system. The user should routinely take note of a few operational points, eg worm activity, wind turbine spinning, water flow.

What shouldn't I feed my worms?

Be careful what you feed your worms, particularly if you are unaware of its source. Manures, for example, from horses, cattle or dogs often have vermicides still active in it that were designed to kill parasitic worms in the animal. They can kill all your worms in one day. If you use animal manures make sure you know when worming is conducted and avoid using the manure for a few weeks.

Can I feed my worms garden refuse?

Not usually. The ONZITE Wormfarm is designed to break down soft organic waste. Slow composting organic wastes, such as garden refuse are best dealt with by conventional aerobic composting methods.

Should I add water to the Wormfarm?

Watering of the ONZITE Wormfarm system will enhance the production of liquid plant food. Food wastes are approx 80% water, which is released as the worms break them down. This will tend to stay in the bedding for a long time before eventually draining out. Any dry material such as old manure, newspaper or cardboard should be pre-soaked before being added.

Will I get too many worms?

No, you can never have too many worms. They will regulate their population to the confines of available space and the amount of food you give them. Worm concentration should reach capacity (about 15,000 to 20,000 worms) after 2 - 5 years.

Will the Wormfarm attract flies?

No, the Wormfarm is fly-proof against household flies. Sometimes the very small vinegar fly (often mistaken for the fruit fly) gets in, but these do not harm. However, very large numbers of the vinegar fly may indicate that you are feeding your worms too much and may be a prelude to problems such as offensive odours. To eradicate vinegar flies, slow your rate of feeding to what the worms will eat on a daily basis and ensure that freshly added wastes are covered by a moist newspaper

Will the Wormfarm smell?

The only smell associated with a well maintained OnZite system is a pleasant rainforest odour. If you’re OnZite has an offensive smell, it is an indication that anaerobic bacteria have built up in the system in uneaten food wastes.

What about holidays?

Leaving an established Wormfarm for 3-4 weeks without constantly adding food is not a problem. Just feed the worms a good quantity of food waste before your leave. These systems are ideal for situations such as holiday houses etc or if you take an extended holiday. The worm population will survive very well with periodic use. Worm eggs lay dormant if the system is not used for extended periods. They hatch once the system is used again.

What household detergents can I use?

As detergents are heavily diluted with water, normal cleaners are suitable. Undiluted bleach and dishwasher use would be the only exception. There are certain dishwasher detergents available that are suitable.

How much will my worms eat?

This depends on how many worms you have. Worms can eat up to half their own body weight every day and can double their population every few months. 2 kg of worms will recycle 1 kg of organic waste in 24 hours.

How can I help the worms to eat more?

Worms will feed at a faster rate once they have adapted to any new food source. Worms will also eat more if food waste is cut into small pieces, mashed or processed. Controlling temperatures to around 70 degrees F/24 degrees C will improve the overall performance of your system. Worms will leave very acidic food such as onions and orange peels until after they have eaten their preferred foods. A handful of garden lime (or crushed oyster shells or ashes from a fire) every few weeks will help to balance the effect of acidic foods. Since they consume up to half their own body weight each day, the fatter they are the more wastes they will eat.

What happens if I hold a large function?

The system was designed with a huge resource-load processing threshold. This allows resource-volume fluctuations to be managed with ease.

As a guide, worms will eat anything that was once living including:

  • Left over vegetable scraps, fruit and vegetable peelings, Manure (well aged),
  • Tea leaves/bags and coffee filters and grounds, Vacuum cleaner dust,
  • Hair and nail clippings (also pet),
  • Torn up newspapers, egg and pizza cartons (soaked first), Crushed egg shells (these will help with the pH balance).
  • The greater the variety of material you use the better it will be!!

Technical Questions

What is the minimum gradient required for the gravity system?

1 in 40 is the minimum gradient. This should be in the general direction of the effluent disposal area.

Is there a minimum or maximum distance of the tank from the house or is that dependent upon the gradient?

We have seen the tanks installed up close to the house but a recommended distance would be between 10 and 40 metres. Once it gets past 40 metres on a shallow slope there are possible issues with solids not travelling the full distance

What is the height of the wind driven vent?

The height of the vent pipe is dependant on the surrounding wind shadowing. We do want it in clear air so it can be as low as 1 metre if it is out in the open (and there are no children around). You don’t really need to power the venting as it is a natural flow of air encouraged by the turbo vent.

How long must the effluent trench system be? Is a reserve area required?

This trench length depends on the type of soil & the number of bedrooms in the house, each bedroom equates to 2 people producing liquid waste and on tank water it is approx 110 litres per person per day. A reserved area is encouraged whilst the trench lines are new and possibly soft but after that the liquid is deep under ground (600mm to the trench base). It is never wise to regularly drive over trenches

What is the base costs of the OnZite Worm Farm system excluding effluent trench earthworks and plumbing from house to the tank?

The OnZite Gravity Wormfarm and its accessories sell for $5450 ex GST ex delivery and installation.

Have more questions?

Call Christopher on 0408 335 612 or via contact form