jolt Posted November 30, 2014 Share Posted November 30, 2014 Just got my Hanna Alk kit and also a new Red Sea titration alk kit. Measured my tank twice with both. They were each self-consistent between the two tests. Results: Hanna: 8.176 dKH (146 * 0.056) Red Sea: 8.7 dkH The Hanna instructions say it can be off by +/- 5%, so if it was off on the low side then actual dkH could be as high as 8.58 (8.176 * 1.05) which would put it pretty close to the red sea reading. Red Sea claims +/- 0.14 dkH accuracy, which if it is reading on the high side could put the reading at 8.56 dkH for the red sea kit. Of course with red sea it is really up to my judgement on when the color change kicks in. I think I am at least consistent if not totally accurate on that one. Whenever I run back to back tests I do get the same number. I guess one approach moving forward would be to use both kits and take the average but that sounds like too much work. Instead, I was thinking to target a reading of something like 9 dkH with the hanna and just try to consistently maintain that, accounting for +/- 5% slop that leaves things in a safe range. Any thoughts, comments, suggestions? Quote Link to comment Share on other sites More sharing options...
Bpb Posted November 30, 2014 Share Posted November 30, 2014 (edited) Use one kit only and keep the other as a backup would be my plan. Hypothetically if you're using the Hanna checker exclusively, and you're down to your last packet, take a simultaneous Red Sea reading and just keep it stable. Since they both read in the 8-9 area I wouldn't split hairs over pinpointing which one is actually correct, I'd rather be concerned with the precision and shoot for the same reading with the same test every time. Now....if one read 7.5 dkh and the other read 12.3 dkh, then I'd be concerned. Edited November 30, 2014 by Bpb 1 Quote Link to comment Share on other sites More sharing options...
victoly Posted November 30, 2014 Share Posted November 30, 2014 I like the hanna simply because of the speed. IMO you should be less interested in the nominal results (unless you're on the fringe of acceptable range) and more on rate of change. Quote Link to comment Share on other sites More sharing options...
jolt Posted December 5, 2014 Author Share Posted December 5, 2014 Ty and I got together today to compare his Hanna Alk meter with my new red sea pro test kit. We also compared to the Hanna alk calibration kit that he purchased. The ideal reading for that is 100ppm. It looked like this (hopefully Ty will fill his in). The Hanna Alk numbers are reported in dKH (0.056 * ppm) while the calibration numbers are in ppm. The delta is calculated as red_sea - ((hanna_calibration/100)*Hanna_Alk). In both cases we saw Red Sea reading approximately 0.6dKH higher than what appear to be reasonably calibrated Hanna meters, and we repeated the tests twice to see that we got the same readings consistently. Hanna Alk Red Sea Alk Hanna Calibration Delta Jim 8.176 8.7 99 .61 dKH Ty 106 1 Quote Link to comment Share on other sites More sharing options...
victoly Posted December 5, 2014 Share Posted December 5, 2014 im gonna need that data for science please 1 Quote Link to comment Share on other sites More sharing options...
FarmerTy Posted December 5, 2014 Share Posted December 5, 2014 Ty and I got together today to compare his Hanna Alk meter with my new red sea pro test kit. We also compared to the Hanna alk calibration kit that he purchased. The ideal reading for that is 100ppm. It looked like this (hopefully Ty will fill his in). The Hanna Alk numbers are reported in dKH (0.056 * ppm) while the calibration numbers are in ppm. The delta is calculated as red_sea - ((hanna_calibration/100)*Hanna_Alk). In both cases we saw Red Sea reading approximately 0.6dKH higher than what appear to be reasonably calibrated Hanna meters, and we repeated the tests twice to see that we got the same readings consistently. Hanna Alk Red Sea Alk Hanna Calibration Delta Jim 8.176 8.7 99 0.61 dKH Ty 9.6 9.5 106 0.67 dKh Added my data. Quote Link to comment Share on other sites More sharing options...
Bluemoon Posted December 5, 2014 Share Posted December 5, 2014 (edited) we're gonna need some sigma plot analysis and a fancy graph to make this science official.... .6 deviation makes me question the competency of one of reagents used...but not enough to really care to figure it out. I got a new redsea kit last week too and am getting a little variation from the numbers i got from the last batch, using the same exact methods. I chalk it up to poseidons will. Getting a truly accurate result with our relatively inexpensive equipment is a crap shot IMO As long as your personal testing is consistent though, you may not have legitimate quantitative data, but atleast you have a relative feel of things changing. for the engineers lurking... Sent from my iPhone using Tapatalk Edited December 5, 2014 by Bluemoon 1 Quote Link to comment Share on other sites More sharing options...
jolt Posted December 5, 2014 Author Share Posted December 5, 2014 Ty - how did you get the .67 delta number? Something looks funny .... Quote Link to comment Share on other sites More sharing options...
FarmerTy Posted December 5, 2014 Share Posted December 5, 2014 Ty - how did you get the .67 delta number? Something looks funny .... I just plugged it into your formula sir. Sorry, did I calculate wrong? I blame my clownfish mating if that's the case. 1 Quote Link to comment Share on other sites More sharing options...
jolt Posted December 5, 2014 Author Share Posted December 5, 2014 You are right! The formula does not lie. That's why they don't let me do math in my head at work 1 Quote Link to comment Share on other sites More sharing options...
jolt Posted December 5, 2014 Author Share Posted December 5, 2014 At this point I feel confident now in sticking with just the Hanna, with an occasional spot check by Red Sea, expecting about .6 higher Red Sea. Given the range indicated by the two kits I am going to target 8.5 dkH on the Hanna for now. I agree with everyone's advice: one measurement approach and keep dKH steady. Thanks Ty for your help! 1 Quote Link to comment Share on other sites More sharing options...
Sascha D. Posted December 5, 2014 Share Posted December 5, 2014 Personally I prefer the Hanna. An acceptable range for me above 140ppm. Quote Link to comment Share on other sites More sharing options...
FarmerTy Posted December 5, 2014 Share Posted December 5, 2014 At this point I feel confident now in sticking with just the Hanna, with an occasional spot check by Red Sea, expecting about .6 higher Red Sea. Given the range indicated by the two kits I am going to target 8.5 dkH on the Hanna for now. I agree with everyone's advice: one measurement approach and keep dKH steady. Thanks Ty for your help! No problem Jim! Thanks for letting me use your Red Sea kit to doublecheck myself. It's always fun to dive back into the science every once in awhile instead of just taking things for granted. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.