queloque July 23, 2009 Share July 23, 2009 What has been done to lower 8.8 PH which is what my Manassas water reads even after RO filtration? Thanks Link to comment Share on other sites More sharing options...
lhcorals July 23, 2009 Share July 23, 2009 What has been done to lower 8.8 PH which is what my Manassas water reads even after RO filtration? Thanks I dont think your test kit is being very accurate. Usually the water authorities try to get PH around 7 to 7.5 i am pretty sure. How old is your test kit? Link to comment Share on other sites More sharing options...
queloque July 23, 2009 Author Share July 23, 2009 I dont think your test kit is being very accurate. Usually the water authorities try to get PH around 7 to 7.5 i am pretty sure. How old is your test kit? I bought it about 2 or 3 months ago at Wally's. Link to comment Share on other sites More sharing options...
lhcorals July 23, 2009 Share July 23, 2009 I bought it about 2 or 3 months ago at Wally's. What brand? Link to comment Share on other sites More sharing options...
queloque July 23, 2009 Author Share July 23, 2009 What brand? API Saltwater master test kit Link to comment Share on other sites More sharing options...
lhcorals July 23, 2009 Share July 23, 2009 API Saltwater master test kit Not saying anything bad but i really dont like that brand. Never got same test results from same sample. Just my .02 Link to comment Share on other sites More sharing options...
zygote2k July 23, 2009 Share July 23, 2009 Have someone test it, then worry about it. Link to comment Share on other sites More sharing options...
jnguyen4007 July 23, 2009 Share July 23, 2009 If you want, bring your water by my house tomorrow or Friday and we can test your water. Link to comment Share on other sites More sharing options...
queloque July 23, 2009 Author Share July 23, 2009 If you want, bring your water by my house tomorrow or Friday and we can test your water. I think I will do that. Thanks. Link to comment Share on other sites More sharing options...
queloque July 23, 2009 Author Share July 23, 2009 What brand do you guys recommend. I have three test kits. Two from the API. I just tested with the other API tester and it reads 8.2 Link to comment Share on other sites More sharing options...
Origami July 23, 2009 Share July 23, 2009 (edited) Forget it. It's not a bad test kit. It's a bad test approach. pH of RO/DI water varies wildly because of the relative lack of ions present to buffer it. You really can't trust the reading that you're getting when using test kits or pH probes in RO/DI water. Test your saltwater after it's been mixed and has aged a day or two so that it's CO2 content equalizes with the air. Interested in a more technical discussion? Read this: http://reefkeeping.com/issues/2005-05/rhf/index.php From the article (by Randy Holmes-Farley): "The pH of highly purified water is not accurately measured by test kits, or by pH meters. There are several different reasons for this, including the fact that highly purified water has very little buffering capacity, so its pH is easily changed. Even the acidity or basicity of a pH test kit’s indicator dye is enough to alter pure water’s measured pH. As for pH meters, the probes themselves do not function well in the very low ionic strength of pure freshwater, and trace impurities on them can swing the pH around quite a bit. " Edited July 23, 2009 by Origami2547 Link to comment Share on other sites More sharing options...
Boret July 23, 2009 Share July 23, 2009 Whoa! I didn't know that. Thank you Tom!! I always check the pH of the new salt water before I do a water change. I make sure I match salinity, temp and pH. Well, salinity I tend to make it a bit higher on the new saltwater to compensate for some of the salt lost due to salt creep and skimming. I never tried checking the RODI for pH and I am glad queloque asked, I would freak out too if I find those values. Link to comment Share on other sites More sharing options...
queloque July 23, 2009 Author Share July 23, 2009 (edited) Forget it. It's not a bad test kit. It's a bad test approach. pH of RO/DI water varies wildly because of the relative lack of ions present to buffer it. You really can't trust the reading that you're getting when using test kits or pH probes in RO/DI water. Test your saltwater after it's been mixed and has aged a day or two so that it's CO2 content equalizes with the air. Interested in a more technical discussion? Read this: http://reefkeeping.com/issues/2005-05/rhf/index.php From the article (by Randy Holmes-Farley): "The pH of highly purified water is not accurately measured by test kits, or by pH meters. There are several different reasons for this, including the fact that highly purified water has very little buffering capacity, so its pH is easily changed. Even the acidity or basicity of a pH test kit’s indicator dye is enough to alter pure water’s measured pH. As for pH meters, the probes themselves do not function well in the very low ionic strength of pure freshwater, and trace impurities on them can swing the pH around quite a bit. " But I tested the water in my tank as well and get the same reading of 8.8 except from the third test kit that gave me an 8.2 reading. Edited July 23, 2009 by queloque Link to comment Share on other sites More sharing options...
Origami July 23, 2009 Share July 23, 2009 But I tested the water in my tank as well and get the same reading of 8.8 except from the third test kit that gave me an 8.2 reading. That's a different problem, then. In your original post, you described your RO water as testing to a high pH. You really can't rely on such tests to measure pH of highly purified water. I use a pH probe to measure pH. (I keep one in the sump, one in my calcium reactor, and a portable probe on hand as well.) It's important to keep a probe calibrated, though if you are to trust the measurements you're getting. Calibration fluids are available to help in doing that. When a probe can no longer hold calibration, it's time to try rejuvenating it or, if that's unsuccessful, replacing it. If you're tank's looking healthy, I'd be more inclined to believe the 8.2 measurement than the 8.8, but getting a reliable data point seems to be in order. What are your other tank parameters? Calcium & alkalinty, for example. How old are the test kits that you're using? (Do they have a date code or expiration date on the box?) If you bring me a cup of your water, I can give you a measurement if you'd like. I see that James offered the same service. Link to comment Share on other sites More sharing options...
jnguyen4007 July 23, 2009 Share July 23, 2009 I remember someone from WAMAS back when I first joined advising me to take pH reading from the tank and not from the RO/DI water. I think it might have been YBeNormal. Queloque, you have both Tom and I who can help you test the pH on your water. Link to comment Share on other sites More sharing options...
queloque July 23, 2009 Author Share July 23, 2009 (edited) I remember someone from WAMAS back when I first joined advising me to take pH reading from the tank and not from the RO/DI water. I think it might have been YBeNormal. Queloque, you have both Tom and I who can help you test the pH on your water. Well the initial test were from the tank that gave me the high reading. So I was curious and decided to test my ph level from the filter so I tested that too and got the same reading. I should have been more clear in the initial post. @jnguyen4007 - Yeah, I'll stay local and stop by your place. But in the meantime what is the most reliable off the shelf brand? @Origami2547 - I don't know the numbers off the top of my head but my paremeters were what was recommended based on the testing kit for Calcium and Alk. I didn't see any dates on the testing kits. I'll look again. I have a shipment of The 2 part kit coming in from Bulk Reef Supply today. So I will be testing again after work. Is a PH probe more reliable than the little kits in the box? Edited July 23, 2009 by queloque Link to comment Share on other sites More sharing options...
Origami July 23, 2009 Share July 23, 2009 Is a PH probe more reliable than the little kits in the box? If you take care of it and calibrate it from time to time with a decent standard, yes. Especially compared to kits that use color charts where so much can be subject to lighting, reading technique, interpretation, etc. Kits that use titration and a sharp color change are more reliable than kits that use color charts because the endpoint is more clearly recognized. Still, though, all titration kits are not the same and, therefore, don't give you the same reading. Different manufacturers use different chemistries resulting in different endpoints. This can lead to different readings (close, but different). There's a really good article here on pH: http://reefkeeping.com/issues/2007-05/rhf/index.php Scroll a little more than a third of the way down to the section titled, "How is pH Measured," and read through it. It answers your question directly. Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now