I'm thinking of getting a ph meter to use for the spa, I had one a while ago for my aquarium and miss the convenience.

Are the cheap pen types worth anything? Or should I get something better/more expensive? Anyone have specific recommendations?

Tell me where you get one of those and I'll try it out myself. Seems like a pretty slick device.

I've wanted to get one, haven't justified the cost yet. I have a ready supply of drops. Accuracy is the only thing I would be concerned about, and what I would do is use the drop method to verify the PH meter is working accurately. Use a range of PH levels for the test, from alkali to acid. If all seems to be on par, there wouldn't be any difference in my opinion.

You can get pen types like this one http://www.marinedepot.com/aquarium_controllers_portable_pH_meter.asp?CartId= for about $50. You can also buy essentially the same device direct from China for about $20 thru ebay and some other sites http://cgi.ebay.com/Digital-pH-Meter-Tester-Swimming-Pool-Water-Garden-p3_W0QQitemZ160024126416QQihZ006QQcategoryZ20729QQrdZ1QQcmdZViewItem This http://www.marinedepot.com/md_viewItem.asp?idproduct=AM1111 was the one I had before, worked well for a long time in a salt water tank, about $90. These all use regular ph electrodes which should be kept wet between uses, e.g left sitting in DI water. You do need to check the calibration from time to time somehow, either by buying the calibration fluid or making your own (recipes are on the net). If you have deep pockets you can spend big bucks at a lab supplier like cole parmer " title="Laughing" />

I really don't think you need to be that precise with it. We aren't building a bomb, just balancing bath water! LOL

Gawd... I hate buying anything on the internet. " title="Twisted Evil" /> Lol... Just kidding. Maybe I'll just go down to my local pikes nursery and see what they got... better yet, freakin Walmart. Yee haa... And in the land of fruits and nuts of spa `whater` chemistry, who says you ain't needin bum buildin akeracy to keep the tub up to snuff? Gawd man, what a can-o-worms to open up! Rotflmao! " title="Laughing" />

I know what you mean " title="Laughing" /> The problem is when you've been used to measuring ph in a second to two decimal places, trying to figure out just what shade of orange/pink is on that silly little stick just doesn't cut it any more " title="Rolling Eyes" />

LOL!~ man somone else that wants a PH pen. i'm a reefhead and i use my milwaukee ph meter on my tub. the pens work great and are much cheaper. if you get one just buy a couple of.99 cent packs of calibration fliud. i keep thinking i could use my TDS meter from my RO/DI somehow! i hate trying to decipher color charts. a green house or hydroponic shop will have the little pens locally if you don't want to buy online.