PH

[alexwolf]

I just installed my Aquacontroller, and the PH is reading 7.91. Stupid question, how do I raise it?

[GaryP]

Is it calibrated?

[alexwolf]

They said it comes calibrated.

[GaryP]

I'd double check it before you start making any changes to your pH. There's no telling how long it has been sitting on a shelf somewhere.

Gary

[cbazhaw]

I ordered 7 and 10 buffer solution and recalibrated mine, it wasn't off by much.

[RobertG]

Be sure to calibrate it after a day or two. Test like you have before. Then dont really on it always, I did & could of cost me dearly. My ph was at 7.72 when it read 8.25 on the meter. Evening Ph, so you can imagine the swing it was taking. Ich was showing, lost one acro. Just dont rely on them.

[astrong]

Your meter is only as accurate as the last calibration. When I worked in a lab at UT we recalibrated our pH meter every Monday. And that meter was several thousand dollars...
They all drift over time. If the probe was shipped dry it will be off. But otherwise you might just have a pH of 7.91. Add KH buffer and get it up to 12-15.

[matt]

DKH of 12-15 is really high, almost double that of natural sea water. There's really no reason to keep alkalinity that high, and it's almost impossible to have an ionically balanced calcium and cabonate situation with carbonate hardness that high. IOW with carbonates that high, you'd have real trouble keeping calcium ions up.

The only reason to keep alkalinity somewhat higher than NSW levels is to guard against quick drops due to increased bio-load and calcification that's typical in an aquarium. But double NSW levels? Not me.

Alex, there's a whole article that Randy Holmes-Farley wrote on ph in the aquarium. I think it's a little more difficult to get a really acccurate ph reading than we usually think. When I was messing around with reactor design and had to have frequent accurate ph tests, I went through a lot of calibration fluid, and always collected water to be tested in a shot glass rather than stick the probe in the tank where it always seemed to be affected by voltage or some electrical interference; maybe from the lights.

Plus, with a shot glass you can hand off the sample to an unsuspecting bystander after the test and offer a toast!

[alexwolf]

Ah, I bought the aquacontroller for future use, to run the CA reactor. Just frustrating, thats all. I will prob order some calibration fluid. Thanks!

[GaryP]

Alex,

I will go along with what others have said and suggest you pay more attention to your dKH than pH. If your dKH is OK, you pH will follow.
My goal on dKH is around 8.

Gary

[CD]

there's a whole article that Randy Holmes-Farley wrote on ph in the aquarium


Online? ...If yes, do you have a link?

Wendy

[GaryP]

Wendy,

Randy has a regular water chemistry column on Advanced Aquarist magazine. Here is the link:

http://www.advancedaquarist.com/

Gary

[JimD]

I have a few extra packs of 7 and 10 calibration fluid if needed...

[GaryP]

Alex,

There's a scientific supply place near your house whgere you can get it. Let me see if I can find it for you. Its on Bandera.

Edit: http://www.analyticalsci.com/

I think I'm going to stop in there and pick up some pH 6.5-10 test strips to use as a quick test. A lot easier and cheaper than a pH meter. No need for calibration. I have some 0-14 strips but they are not specific enough.

Gary

[alexwolf]

I need to order the control module anyway. Thanks guys!