hard water and ph levels

Hi,
I live in a very hard water city, limescale forms on everything. I bought some ph paper strips to give me a general idea, the water (after being sat for 24hours) is around 8.
I add biobizz bloom and topmax orgainc feed/ booster to every watering, will that affect the ph levels?
should I test the water that runs out of the bottom of the pot?
Was thinking of buying some ph down or adding a 50/50 mix of tap and brita filtered water. what do you guys think?

The nutes will bring down the ph down a little bit. You should buy ph down and use a couple small drops to bring to the desired level. I bought ph up and have never used it, ha ha. I say go ahead and get the filter if you only have a few plants going, theres nothing like doin it right!

thanks for the info, I bought some ph down off ebay - PH DOWN PHOSPHORIC ACID 250ML on eBay, also Hydroponics, Plants Seeds Bulbs, Garden Plants, Home Garden (end time 05-Oct-08 13:46:12 BST)

I already have a brita filter and 1 plant only to water. I've read conflicting reports on using filtered water due to the fact that it makes the water too soft.