While we are on the subject of generic brands, have you ever paid $40 for a bottle of weedkiller? Knowing the names of a few basic chemicals can save you a lot of money if you read the label.

The active ingredient in most popular brands of weedkiller is called glyphosate diisopropylamine, otherwise known just as "glypho". It is the stuff that kills plants in such brands as Zero and Roundup, but it is the same stuff in the cheaper brands as well. The active ingredient is usually written on the pack, including the concentration.

The well known name brands charge three times as much for a product that is ten times as dilute. Go ahead, check out the labels, you can buy a litre of generic brand concentrate for $20 or a few litres of very dilute name-brand stuff for $50. Even if you can't pronounce the name it doesn't matter, if you can put the bottles next to each other and check it is the same word then it is the same. Probably made in the same factory also, shipped in in bulk containers and bottled locally in a variety of budget, medium and premium brands.

Fungicides tend to be based on copper salts, it doesn't matter which salt it is because the active ingredient is copper. You can pay $12 for a little bottle of copper hydroxide solution containing maybe one gram of copper, or buy a large bag of copper sulphate for the same price and while you are at it clean the algae off your driveway as well. The only thing to be careful with is dosage, it is quite easy to go overboard on the fungicide when you have a 1kg bag of high purity copper salts.

And then there is bleach. The stuff is cheap and ubiquitous but I do find it amusing that you can go into hardware stores and see it sold for $40 with some exotic sounding name and industrial looking packaging.  I am quite sure it sells too, despite the fact that the same amount of bleach was selling three meters away for a couple of dollars.  Bleach is bleach, even when its got a funny label!

(Just in case you are wondering, I wasn't always a financial planner. I studied chemistry at university. Trust me on this, chemists do not buy premium brands for any domestic chemical or pharmaceutical. You'd be surprised at how many ways basic chemicals are sold at high prices to consumers and how the same basic stuff appears in a variety of products that supposedly do very different things. You'll note, for example, that toilet cleaner usually has the same active ingredient as the disinfectants that you clean the floors with. Why buy the special stuff when you can get a two litre bottle of generic disinfectant that will do the same job at a much lower cost?)