Understanding PH/ALK/CAL

lexluethar

Active Member
Got a few questions about my test results. I just bought a new Alkalinity test kit and I understand the results, but I don't understand the relationship between PH and Cal.
First question is, I originally had a tetra test kit for my PH. It is a liquid test kit and it would consistently read my PH at 7.9, I just tested with my new Seachem multiTest and it read between 8 and 8.1. I realize it isn't that big of a variance, but which would you guys trust?
Second question, my PH is CONSTANTLY low, so the 8.05 wasn't a suprise with the new kit. I've tried a lot of things. Opening a window, turning on room fans, putting a fan on the tank, pointing a powerhead up to agitate the water, and all my water changes (once a week) are mixed and airated for 24 - 48 hours. What is the deal? My PH is always 7.9 - 8.0, my Calcium is always 450 sometimes a bit more (no more than 500), and my alkalinity was just tested tonight and it was between 4 and 4.1.
Sorry for the long story, I just have three questions really...
1)which test kit should i trust or are either fine?
2)why does everything (Alk, Cal) seem great but my PH is always way low?
3)is an alk of 4 okay for saltwater? The test kit said for was on the low end?
Thanks
 

ifirefight

Active Member
Alk 4-4.1 what.....???? mequ/l .. If mequ/l then you are in the high range....if dKh,,,well you have a problem.
 

lexluethar

Active Member
The testkit that i have, the Seachem says 4 - 6 within an aquarium is normal. I believe it is meq/L.
From the instructions "Natural sea water has a total alkalinity of 2-3 meq/L, but aquarium water should have a total alkalinity of 4-6 meq/L. This kit measures total alkalinity"
I did the reference tests on both PH and ALK and they tested within the range they were supposed to. It is a combo test kit, BUT they have difference vials with different liquids, one for PH (add one drop to a vial of the test water) and one for ALK (add one drop to a vial of test water). The measuring meter is the same for both, but for alk it says divide by two.
Am i taking crazy

[hr]
...?
 

ifirefight

Active Member
OK...I dont use Seachem test kits...but I can tell you this. 4-6 is not within the desired range for ALk. 2.5-4.0 meq/l is acceptable OR 7-11 dKh. And yes Natural saltwater is around 2.6 meq/l. You said this kit measures "total" alkalinity...Im not sure if that is different than just plain ole alkalinity. Like I said...Im not familiar with that particular test kit...BTW your PH is fine. PS..check your PM for a helpful link.
 

lexluethar

Active Member
Thanks fire. I'm not sure either, I just never tested alk. When i wondered why my PH was low people said i really need to check alk. So now i've checked it and really don't understand the relationship.
I don't want to just say well PH is okay and Calcium is okay, so i won't worry about alk - ya know?
 

spanko

Active Member
Google
reef alchemy with randy holmes-farley reef aquarium water parameters
Pick the first hit that comes up.
 
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