Hi again Kirsty,
I was thinking about your cloudy water from the tap and I have a few guesses / suggestions. First of all, I only went from the information from you so far so all my conclusions could be very wrong as I don’t know many of the details.
Firstly, you mentioned that your water is soft with the PH on the acidic side. So, I am ruling out any inorganic precipitation / stirred sediment / etc. And this makes me totally wondering what on earth is in your tap water which is “safe for humans”, should be organic (soft water, so not too much of hardiness) and at the same time does not settle... Surely, whatever that is should not be there?...
You said the cloudiness does not settle... Did you try pouring a glass of water from the tap and leaving it for a while? What happens? Often water comes out cloudy because of gas content – and if stood for a while it clears. If this is the case with the “glass of water” experiment, and your tank water is STILL cloudy, then I would suggest different reasons: high gas content in your tap water (high pressure in the mains) and something absolutely different in your tank – similarly looking cloudiness which is, in fact, a bacterial bloom... That can be addressed pretty much “once and for all”. Can you comment on this please? I am sure Sue will have some suggestions. I like Chemistry but my University degree was in a completely different field and Sue is a chemist by education.
Another thing – I have gone through your posts and discovered that you wanted to keep live plants. If this is the case, Purigen will be your plants killer... Plants absolutely NEED Nitrates to survive (they are one of their essential “foods” – yes, plants do need nutrition as well!). Purigen will “suck” all those Nitrates starving the plants. So, no aquascaper (myself included) would ever use Purigen – unless there is an emergency (which, frankly, does not happen if everything else is done properly).