pH probe and low pH questions

[TriggerHappyDude]

Ok, trying to calibrate a pH probe from Pinpoint that I'm using with my ReefKeeper Elite.

I followed the RKE steps to calibrating it using two calibration solutions, pH 10.0 and ph 7.0.

Then right afterwards I rinsed the probe in RO/DI water, and tested it in the same two solutions.

Both were really close, 9.90 and 6.99...so I would assume at this point the pH probe is fairly accurate.

 

My pH in the tank now is reading 7.52 according to the probe.

So I tested the water using my API test kit, and its reading right around 8.3, a lighter purple than 8.4 but not as brown as 8.2, and FOR SURE not between the 7.4 yellow/orange and 7.8 light brown.

 

So what's off? My solution you think is bad? Its Coralife, not Pinpoint, but the guy at the LFS said that didn't matter when he sold it to me. Process of elimination tells me its the solution, agree/disagree?

[lakshwadeep]

I would trust a pinpoint solution over a coralife. Rinsing with RO/DI and then testing the same calibration solutions isn't really going to tell you anything new. If one or both calibration solutions are wrong, you will have problems. Read this for pH calibration info:

http://reefkeeping.com/issues/2005-02/rhf/index.php

[bird]

You might also consider this.

I struggled with the ph readings from my Reefkeeper 2 for several months (new $50 Pinpoint ph probe). It seemed that I would have to recalibrate ever couple of weeks or so.

When I did this was when my reading went below 7.8.

I used fresh calibration fluid each calibration.

Seemed to work just fine-for a week or two, then readings went way to low and did not match titration readings.

I unplugged the fairly new ph probe and now do not worry about the ph as long as my corals and fish look fine.

It has been a couple three weeks since I shut it down and everything is still fine with regular water changes. I keep excess food out, remove anything that has died (nothing so far but always on the look out) and concentrate on calcium, magnesium and alk levels instead.

 

I am no expert pertaining to ph but in most all the articles I have read from well respected authors, none ever stated that exact ph levels were detrimental to keeping a healthy reef.

In fact it is easier to send a reef system southward when worrying about the ph and adding additives here and there to keep it at a specific level.

 

Focus on your calcium, magnesium, alk levels and your ph will fall where it needs to. JMO

[MikeTR]

I agree with bird.. the only time i've had problems was early on in the hobby trying to chase the perfect pH.

 

correction... the only time i've had stuff melt away was early on.. i've had a few problems here and there maintaining alk and calc levels but no loss from it. Had a few LPS look sad for a few days but have all recovered

 

Now...since you spent so much friggin money on the RKE... just get some different calibration solution and try again... but don't make any corrections based upon your readings yet until you can get confirmation it's working.

[TriggerHappyDude]

I agree with bird.. the only time i've had problems was early on in the hobby trying to chase the perfect pH.

 

correction... the only time i've had stuff melt away was early on.. i've had a few problems here and there maintaining alk and calc levels but no loss from it. Had a few LPS look sad for a few days but have all recovered

 

Now...since you spent so much friggin money on the RKE... just get some different calibration solution and try again... but don't make any corrections based upon your readings yet until you can get confirmation it's working.

 

That's exactly what I tend to do, nothing has been added yet, I'm not convinced my pH is this low.

I'm buying some new Pinpoint calibration packets and will see what it does, I have a feeling the other Coralife solutions were bad, or old...

 

Oh I've also just ordered a Mag kit and supplement...will be keeping an eye on it.