PH meter buying advice needed

[PhatJay]

I need to get a PH meter, the ones from the grow shops are over twice the price of other ones I have found, that are sold by aquarium shops. Is there a big difference in PH meters? Are there any particular specifications I should be looking for?

Also what is the difference between meters that require PH-03, PH-04 or PH-07 calibration solutions? They all seem to measure the same PH range and have the same tolerances.

I found these 2 on amazon, only differences I can see is that the 1st one is cheaper, heavier and comes with calibration fluid. The second one mentions calibration via trimmer and calibration fluid is extra.

ATC PH Meter Pool, Fish Pond & Marine Aquarium: Amazon.co.uk: Garden & Outdoors (http://www.amazon.co.uk/gp/product/B000RL8LOY/sr=1-1/qid=1265322488/ref=olp_product_details?ie=UTF8&me=&qid=1265322488&sr=1-1&seller=)

Pen Type pH Meter - PH-03: Amazon.co.uk: Kitchen & Home (http://www.amazon.co.uk/Pen-Type-pH-Meter-PH-03/dp/B000XQ8T2C/ref=pd_rhf_shvl_9)

Or I could go to a grow shop and pay even more. :/

[mmjhelpsalot]

buy a hanna meter, normally you get what you pay for with ph meters, and do not check the ph of water with low ppms, such as RO/DI, distilled, etc. Add nutes then check ph. I killed a ph meter electrode from that mistake.