PH tester

Hi all.
Sorry if this has already been asked, but I could not find exact answer to my questions.

I am considering buying a ph tester to test the water when brewing, and also to check my Star San ph level - I read,somewhere that if Star San ph goes above 3.5, it's not god anymore.
So, here are the questions - please consider I am an amateur home brewer, so I don't need/want anything too sophisticated like a $100+ tester that would be used for a larger scale production.

- I read that the best is to have 2 points calibration. Is this a must? Can I go with 1 point calibration?
- How often do you need to calibrate these things?
- The pouch of calibration "stuff" that comes with it is good for how many uses? Where do you get more if needed?
- How long is this device good for, considering I only do 10 - 15 batches a year? I think I read somewhere that it wares out fast...
- Would the $20 price range I can get on eBay be good enough?

Any advise would be good.

I used to do hydroponic horticulture and used a pH tester. Heres some info from my experience. First, if you can afford it, buy one where you can replace the probe if it does wear out. This provides huge savings over the long run. You should be able to find one around 50-60 dollars. Once you take it out of the package and calibrate it don't let the probe dry (always store in 7.0 solution). If it does you have to recalibrate it and it goes bad sooner. I would recomend recalibrating every two to three months. If you always rinse in distilled water after each use and before calibrating...the solution will last a long time (shake off very well before putting it into the lower pH solution to prevent changing the pH of it). Make sure that when you store the solution it is sealed well. If any moisture evaporates it wont read at the correct pH for calibration. As for the 2pt vs 1 pt im not entirely sure (correct me if wrong) but i think 2 pt calibration makes a more accurate measurement. You can buy the solutions/pH meters/probes at most hydroponic horticulture stores. hope this helps

For calibration, you will want to utilize at least two points (one above the max expected range, one below), three is preferable.

For storage, keep the probe moist at all times, never in distilled water (best to use storage solution, or 4.0 buffer, or even tap water).

We use this at work for quick measurements: http://www.amazon.com/dp/B004G8PX72/?tag=skimlinks_replacement-20. Replaceable probe, three-point calibration, waterproof, automatic temperature compensation.

Zoltanar said:

please consider I am an amateur home brewer, so I don't need/want anything too sophisticated like a $100+ tester

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dutchoven said:

We use this at work for quick measurements: http://www.amazon.com/dp/B004G8PX72/?tag=skimlinks_replacement-20. Replaceable probe, three-point calibration, waterproof, automatic temperature compensation. Price: $115.00 & this item ships for FREE with Super Saver Shipping

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I guess it boils down to where you see yourself as a brewer in a couple of years. If you think you're still going to be doing a batch here and there, and not really worried about EXACTLY what's going on in EVERY aspect of your brew, the $20 meters will give you an idea of what's going on.
If you think you might want to push yourself to become an ever more skilled brewer, maybe a more expensive meter is a good investment.

Cheap meter pros:
- Cheap
- Give you a basic idea of ph. Probably good enough to get you close
Cheap meter cons:
- Probe tip is not replaceable. If it dries out, the whole thing is trash.
- 1 point calibration does not correct for the whole range of ph you could be seeing. It might be quite accurate measuring starsan (3.3), but maybe off when measuring your water (probably 6 or 7 ish).
- Not temperature compensated. Readings must be done at 20 C, not always very convenient when in the middle of a mash.
- Tip still must be stored wet, in storage solution (just like the expensive types).

I have a Hannah Phep 5 and love it. I paid a little over $100 for it, the 2 calibration solutions, and the buffering solution from MoreBeer. Yeah, it's pricey, but I'll probably never need another one. Oh, and it does all the things I mentioned in the cheap meter cons

+1 to the Hanna pHep 5 (98128) meter for about $85 with about $30 for storage, cleaning and buffer solutions.

Ok guys. Thanks for your opinions. I guess I'll save for a more expensive one. I did not know you had to leave the probe wet. This was a surprise to me. From what I understand, it is worth it to spend a bit more on something better quality.

Thanks again - you guys probably saved me 20 - 30 $
....now, how about a refractor . (...or refractometer???)
No, seriously, what do you think about these?

http://www.ebay.com/itm/RSG-100ATC-..._Equipment&hash=item45fdff45f6#ht_1484wt_1163

I think that's the cheap one I have. It's been great. I've checked it against my hydrometer many times and it's always accurate. Very, very helpful for pre-boil gravity checks. I don't see any reason to spend triple the cost on the ones from homebrew stores.

If the images on the eBay page are correct, that refractometer suffers from the same issue as mine: the SG scale is inaccurate, so you have to use the Brix scale and convert to SG.

If you zoom into the Brix/SG scale image, and look at the 20° Brix line, the corresponding SG is around 1.076, quite a distance from the correct 1.083.

That said, as long as you're aware of that defect and don't mind converting from Brix - and assuming the thing actually is accurate at reading Brix, of course, and the ATC works - the price is certainly attractive...

Cheers!

Thank you guys for the information.
I just ordered that one this afternoon.