Richard,
I think you can forget the results from your strip test kit all together. You can definately throw out the kit too. I think its safe to say that it has been fairly well proven to be completely unreliable. The alkalinity, hardness and pH were way off. I think you can say that all the other results from that initial kit test you did can be forgotten. Now that's not to say the pool guys results are 100%, but I think its safe to rely on them as a good enough guide.
So, that being said, I completely change my tune about your bore water (to a certain extent). Whilst Dr Smurto is advising to have certain things tested, he is really coming from an all grain brewing perspective I think. There's nothing wrong with that, but you have stated you are only interested in kit&kilo or extract brewing at this stage. My main concern for your water was the initial results of your kit test. I think you can now ignore those concerns (my specific concern was the low pH and the high chance that such low pH ground water could leach heavy metals and other nasties into it, as well as the effect it would have on your metal piping). This concern is alleviated a great deal by the pool guys readings of your bore water pH that are HOPEFULLY reliable enough. I think this reliability is born out in the Iron level of 0.2 mg/L. A really low pH would generally have a higher Iron content so I'd be happy that the pool guys pH result is roughly right (or at least not in the 4-5 range).
IF the metal content for copper (0mg/L) and iron (0.2 mg/L) are accurate you SHOULD be ok. The reason I highlight should is that the iron is close to the maximum for the NHMRC aesthetic value (0.3 mg/L), which means it might be visible (discolouration left on clothing washed with the water) or have an iron taste beyond this level. This is easy to test. Taste the water, if you have an iron taste or that blood nose odour in your nose then it may affect the flavour of your beers. If you can't detect this, then it's unlikely you will taste it in your beer.
Now as I and others have said the pH won't affect your brewing to any great extent (for those that groan at this remember he is extract brewing and only adding the water to his kit) so given that both your bore water and rain water are 6.4 and 6.5 respectively I suggest you can rest easy about your copper pipes. The range between 6.5 & 8.5 is the recommended pH for municipal water. If you really wanted to push the pH up to 7 or higher in order to absolutely over-the-top ensure nil copper was leached from your pipes, you could add some calcium carbonate or even cheaper, bicarbonate of soda. Bicarbonate of soda does add sodium to your water (given you live close to the sea I'd keep this down) and calcium carbonate does increase the hardness levels in your already "up-there" rain water. The amounts we are talking about are tiny. For Calcium carbonate it would be something close to 0.02 gm/L to bring it from 6.5 up to 7.5 or similar, that is 300 gm per 15,000L tank. In regards to the condition of your copper pipes, I honestly think the pH at 6.4 is not worth worrying about though (especially considering the buffering effect of the hardness in your rain water). I'm not advocating adding anything to your water at this stage, only giving you the info incase you are keen or the tanks empty of rain water and you want to harden up the softer bore water (to prevent pipe corosion).
The way I read it, after 17 years of drinking the stuff, you aren't worried about high levels of nasty bacteria in your water right? And given many things can kill bacteria (boiling, alcohol, etc) they can easily be overcome. I am pretty sure the reason the water testing facilities want your sample within 24 hours is because of the E Coli and other bacteria testing they do. I think after 24 hours the results can't be considered reliable, because of natural die off or breeding of the bacteria, which can effect the levels giving false results. So, if you aren't worried about the bacteria in the water then you can ignore that 24 hour requirement.
So in saying all of that, would I still get the bore water tested. Yes I would and despite the cost (although keep shopping around for a better price).
Maybe it's because I'm paranoid about
water that has been sitting in the ground and the lack of knowledge about the make up of that ground. If I had the choice I would get it tested for hardness, pH, chloride, sulphate, calcium, magnesium, potasssium, sodium, iron, manganese, copper, arsenic, cadmium, lead and see if they could test for chromium. My thinking behind having so many tested is less for the brewing or corroding pipe side of things, but for the health implications of any of the heavy metals or sulphate being above maximum levels recommended for health safety. See NHMRC guidelines for maximums https://www.nhmrc.gov.au/guidelines-publications/eh33
