1000 -1500m2 is the minimum size of greenhouse necessary for commercial operation, possibly larger if it is to be the sole family income.

For efficient operation and optimum crop health, a height to the wire of at least 3m is recommended, less than 2.5m reduces your chances of growing successful crops.

Lack of sufficient venting can make humidity levels very hard to control and lead to fugal diseases. Effective vent systems should actually draw warm air from the greenhouse.

Rows aligned North/South give best use of light..

Heating Systems: 
The most efficient heating systems are hydronic, i.e. heated by hot water pipes. Waste oil burners that heat the water can require a lot of maintenance. The heating system needs to be capable of giving 17 degrees at night and automatically lift one degree at dawn to avoid condensation on the fruit.

"Optional" Extras: 
When comparing the prices of hydroponic systems make sure you have a list of all that is included in the price. Optional extras are often items that are required from the start and vital for the growing of a quality crop, e.g. pollinators, layering bobbins, EC & PH meters, spraying equipment.

Water Requirements: 
The quality of water is important. Dam water may need to be filtered or treated to be suitable, you need to be aware of costs involved here.

Power Requirements: 
Power needs to be adequate to run all electrical equipment simultaneously.

If you are new to hydroponics then consultancy for the first crop is advisable. Check the growing credentials of the consultant offered to you by insisting on talking to growers who have used the service for a prolonged period, more than one year, and seek information from as many different sources as possible (e.g. TAFE, library, Internet.)

Marketing Arrangements: 
Be wary of any "guaranteed price" offers, the reality is that prices fluctuate with the seasonal supply and demand and the quality of fruit you produce. It is often difficult to produce top quality fruit in your first season and impossible in an inadequate system. It is important that you explore marketing options for yourself and talk to market wholesalers and packhouse operators do determine which arrangements suit you best and to find someone you are comfortable to work with. After all you are trusting them with your produce. An important question to ask is-"What is the time from delivery to you receiving payment?" In the early stages of a crop this can be vital as it may have been three months without income since the last crop. 

Questions To Ask Experienced Growers When Evaluating A Hydroponic System: 

1. How good has the backup service been from the company that built their greenhouse system?

2. How much did they spend on optional equipment after the hand over?

3. How efficient is the heating system and what are the running costs?

4. What are the level and consistency of the crop consultancy they are receiving?

   -  7days a week phone or fax advice?
   -  Nutrient formula advice for different crop stages?

5. Was a packing shed supplied with the greenhouse system?

6. Are they happy with -the nutrient run off collection system?

   -  Greenhouse design?
   -  Growing height?

7. Do they experience fungal problems due to poor air circulation and/or inefficient heating?