Ph at 8.6.

[The Floodinator]

New Member here with a question. I used Aragonite(?) rock collected in the Utah desert for the base rock in my reef tank. My ph stays at 8.6. Sometimes drops to 8.5 but never for long. The owner of my LFS new somebody that used the same rock and had really high ph also. Anybody else have experience or knowledge of this? Should I correct ph to 8.2 or not worry? Fish are fine. Open Brain, 2 Torches, Candy and Zoos all doing fine.

[DrBDC]

How are you measuring your pH?

[Boomer]

Where exactly in the Utah desert ? We can find out what kind of rock it is with a geologic map. It can't be Aragonite. If it was, say aragonite, the Calcium and Alk would be through the roof.

Your pH is the limit for a reef. Just make sure the Alk and Calcium do not get to high ==>snow storm.

To lower the pH you could drip in Soda Water or Vinegar. I would not use Vinegar to much in organics.

And have you verified that pH

You live in Ogden UT. I'll look to see what is around you, till you get back to me.

[The Floodinator]

I'm Using a Milwaukee Instruments ph Monitor.

[Boomer]

When is the last time you cleaned and calibrated it. What does a test kit say.

[The Floodinator]

If you look on a map of Utah, follow I-80 from SLC west. You'll see a town called Aragonite. Just to the north of there. Maybe 3 or 4 miles to the north of the freeway. Verified with a Red Sea pH test.

[The Floodinator]

Boomer,
Cleaned and calibrated it maybe 6 weeks ago.

[The Floodinator]

Just a note on the rock. It's light gray to white in color, very porous, and looks like water flowed through it as it formed. I'm told it's a leftover from Lake Bonneville.

[Boomer]

For me that is along time ago. Algae can grow on the probe and raise the pH as it picks up CO2 at the probe algae interface. Whenever there is a reduction in CO2 pH goes up. I don't trust that Red Sea but the reading at least are the same ;)

Why not aragonite ? LR and SB are usually aragonite and they do not do that. One possibility is if there is allot of trapped powdered fines or "points" on the grain surfaces. As particle size decrease solubility increases. But that should stop in time.

What is the Alk and Calcium ?

[The Floodinator]

Alk at 5 Meq/l using Sea Chem test. Cal at 400 ppm using Red Sea Cal Pro test. I'll clean the probe and recalibrate.

[Boomer]

I was just thinkin that :lol:I use to have a Utah internet friend here all the time helping me with chem questions when Randy is gone. He has been MIA for the last few months. We had a long discussion here on his rock like yours. Here is the thread

http://reefcentral.com/forums/showthread.php?s=&threadid=401475&highlight=Bonneville

[The Floodinator]

Thanks for the link Boomer. That is exactly the kind of rock I used. I also went to Stansbury Island for the oolitic sand mentioned in the thread. Still don't know if it's affecting the pH or not though. If I were to drip soda water, is it just trial and error to determin the amount and drip rate? Total water volume is about 140-150 gallons.

[Boomer]

If I were to drip soda water, is it just trial and error to determin the amount and drip rate?

Yes, the drip rate you end up with should control the pH where you want it.