What is Hydroponics?
Do It Yourself
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Hints for Success
Operating Your System
pH for the Gardener
The five nutrient solutions.
Click the image to enlarge.
This Starting Formula has been adapted from Sundstrom's excellent book:
Sundstrom A.C. Simple Hydroponics for Australian and New Zealand Gardeners. 1989. Penguin Books Australia Ltd, Ringwood. Victoria. pp 31 - 34.
The following nutrient solutions are used at fairly dilute rates and must be properly measured out. Do NOT increase the usage of any of them unless you are aware of what you are doing. Nutrient solutions that are too strong, can kill the plant by dehydration.
Prepare the five nutrient solutions below in five different 4 Litre plastic fruit juice bottles. The usage of each varies, e.g., if your nutrient solution tank holds 160 Litres and the usage rate is 1.0 mL/Litre, then use 160 mL of that solution. With a felt pen, number each bottle and list the usage rate, and the amount of that solution you need to use. All weights are in grams and common names are used.Solution #1:
Method of Use:
Do not mix Solution #4 concentrate with any of the other concentrates. Shake each before use to suspend any undissolved matter.
Half fill a 10 Litre plastic bucket with water, and measure each concentrate into the bucket of water. For example, if your nutrient solution reservoir holds 160 Litres, then measure 160 mL Solution #1, 160 mL of Solution #2, 320 mL of Solution #3, 640 mL of Solution #4 and 960 mL of Solution #5.
Pour the diluted nutrient mix into your nutrient solution reservoir, stir well, then measure its pH. Aim for a pH of 6.0 to 6.4
Adjust the pH with dilute Sulphuric Acid. How to make dilute Sulphuric Acid will be explained later on this page.
Weighing out Small Quantities.
Weighing out small quantities of materials may appear daunting, but here is one suggestion that may help. Weigh out eight times as much as you need, then pour it on to a flat surface and divide it in two equal sized portions with a flat knife blade. Now divide the two heaps into four with a cross-cut. Now scrape away three of the heaps and divide the fourth in two and select one. Bingo!
Preparing Dilute Sulphuric Acid.
If this is being done for a School Project, it MUST be done by an adult (it is too dangerous for children).
Select a one Litre plastic bottle with a plastic screw top and fill it to 950 mL with tap water. Wearing suitable eye protection, carefully measure out 100 g (just over 50 mL) of concentrated Sulphuric Acid, and carefully pour into the water in the plastic bottle. It may momentarily boil so slow down the acid addition. When cooled, replace the cap and mark for identification with a felt pen.
Dangerous Chemicals on this Page.
There are several Dangerous Chemicals on this page. They are: Potassium Nitrate.
Potassium Nitrate is an Oxidising Agent and must be kept away from Reducing Agents, and the liquid must be kept off clothing and other organic materials such as paper and wood. Store in a plastic cookie jar with a screw top, and keep the original container sealed between re-filling the cookie jar. Wash hands after handling.
Borax is a Schedule 5 Poison. Store in original container. Wash hands after handling.
Copper Sulphate is a corrosive solid and is corrosive to many metals. Safe to handle with dry hands, but wash hands after handling.
Concentrated Sulphuric Acid.
Concentrated Sulphuric Acid is very corrosive to skin, most metals and most organic materials. DO NOT POUR WATER INTO CONCENTRATED SULPHURIC ACID. .... IT WILL EXPLODE! Wear suitable eye protection and plastic gloves while handling. If spilt on the skin, wash with water immediately. Keep container tightly sealed when not in use (it is hygroscopic ... sucks water out of the atmosphere).
Dilute Sulphuric Acid.
Dilute Sulphuric Acid is no where near as corrosive to the skin as the concentrated version. Do not spill on clothing ... it will eat holes in most fabrics. If spilt on skin or clothing, wash immediately with copious quantities of water. It has a sharp, bitter taste if you accidentally taste a finger after handling it.
If you need clarification on any points, please feel free to E-mail me.
The next page is a brief discussion on the analysis of the Starting Formula.