EBay Ph probes?

[ReefNut]

Hi,
I wondering if anyone here has any feed back ph probes bought off Ebay?
I need a back up and wondering if they are any good.
example:
http://www.ebay.com/itm/pH-Electrod...024?pt=LH_DefaultDomain_0&hash=item53f7a1fd28

Also will they work with Apex controller?

 

[FRY]

http://www.ebay.com/itm/170752579436?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649

i bought 2 of them made a offer for $15 each and they work fine

 

[ReefNut]

Thanks for the reply,
I wound up ordering 2 Pinpoint probes.
Found them at a decent price, so I figured it wasn't worth the risk.

 

[youngfish]

I bought the same thing for $15. But it starts drifting after a month use. My calcium reactor clogged! I wouldn't buy it again. I went with pinpoint probe as well.

 

[youngfish]

If you calibrate with apex, the $15 probe has a narrow voltage range while the high quality one is much bigger.