Help on ph meter please

HI ALL, IVE BEEN HAVING A BIT OF A PROBLEM WITH MY PH

i got my sum ph buffer 4 calibration solution and it says that my ph meter should be reading 4.0but my was 4.7
ive not got my ph meter to read 4.0 when in the buffer but does that mean my ph meter will only read 4.0 reading im confused big time

after i set my ph meter to 4.0 i tested my normal tap water and its now reading 6.9 but before i changed my meter it was reading 7.2 is my meter correct or have i messed my meter up as im new to hydroponic and im running a 6 bucket dwc bubbler system if my ph meter is correct that means my waters have been off from the start off my crop correct?
any1 help me out here please

many thanks
happy growing
peace..

As long as you adjusted the meter correctly in the buffer it should be right, tap water can vary. The meter was reading too high and now it should have the ph 5.8 .

when the meter read 7.2 that sounds about right for tap water, another big thing about ph meters is when they malfunction alotta the times it needs new batteries.

cheers buds yh my ph stays at 5.8 thats my number but ive only today thought about my ph meter being off so my waters have been off from the start of my grow (bastard) but now my meter is correct well i hope ive done it right away my meter read 4.0 in solution buffer 4
so hopefully when it says my ph is 5.8 thats correct?

What is the brand you are using? Hanna/Oakton/Bluelab?

My Hanna has two adjusters, one for 7.0 ph and the other for 4.0 ph
When the meter is in the 4.0 buffer you set the 4.0 adjuster to 4.0 and when it is in the 7.0 you adjust the 7.0 screw so it reads 7.0
Then your meter will read right for a while. But you need to adjust it periodically to keep it calibrated. Hope this helps.