I'm not sure how readily available they are in the UK, but the PinPoint pH meters are excellent and very easy to use.
Been looking on Ebay at available digital PH meters. Prices including delivery upwards from about £15. Has anyone got or used one? Are they recommended? Are the cheap pen ones as good as the more expensive ones?
Yes, I too have an american marine pinpoint ph monitor. Highly recommended.
Here's a link to one on Ebay if you can handle shipping.
http://cgi.ebay.com/American-Marine...oryZ3212QQssPageNameZWDVWQQrdZ1QQcmdZViewItem