Low Alkalinity

[Jiliman]

Hello,
I have a low and not stable alkalinity and I am about to do 20 to 30 gallon of water change on 112 gallon tank today. I made a new badge of Pro-Reef saltwater with 1.026 and 77 degree and let it be mixed for 24 hours. Today I check the water Alkalinity and it shows 6.3 !!! It is ever worse than what my tank shows(6.7)
Should I still do the water change?
Please help me

 

[EricR]

Seems likely (or at least possible) that your alkalinity test isn't accurate,,, old reagent, etc.

I'd verify that against a different method/checker/tester before doing anything else.

 

[DaJMasta]

I'd buffer the alkalinity of the new saltwater to the level you want it at and then make the change, no sense in reducing the level further especially if you're trying to raise it, but it should be easy to mix in a little more and retest.

 

[Jiliman]

Seems likely (or at least possible) that your alkalinity test isn't accurate,,, old reagent, etc.

I'd verify that against a different method/checker/tester before doing anything else.

I am using Hanna alkalinity tester with reagent expires 10/22
I am using the same tester for my tank and it shows different. I was dosing Soda Ash and tester showed my target number but only last 24 hours or less. So I came up with idea of water change to stable it but facing with issue of new badge of saltwater alkalinity level.

 

[Jiliman]

I'd buffer the alkalinity of the new saltwater to the level you want it at and then make the change, no sense in reducing the level further especially if you're trying to raise it, but it should be easy to mix in a little more and retest.

You are asking me to dose the new badge of water with soda ash?

 

[EricR]

I am using Hanna alkalinity tester with reagent expires 10/22
I am using the same tester for my tank and it shows different. I was dosing Soda Ash and tester showed my target number but only last 24 hours or less. So I came up with idea of water change to stable it but facing with issue of new badge of saltwater alkalinity level.

I'm using the Hanna alkalinity dKH checker also.
When my reagent is new, my tests match my LFS tests.
After opening, as the reagent ages, my tests drift lower.

*there's another thread on here where R2R user Lasse proposed refrigerating the reagent (after opening) as a way to potentially prolong it's accuracy,,, which I've now started doing,,, but didn't know about the idea soon enough after opening my current bottle.

EDIT -- so I agree that your new water alkalinity water is lower than your tank alkalinity,,, but I question if both might actually be higher alkalinity than your checker is currently showing. (Just a thought,,, not statement of fact)

 

[bnord]

I'm using the Hanna alkalinity dKH checker also.
When my reagent is new, my tests match my LFS tests.
After opening, as the reagent ages, my tests drift lower.

*there's another thread on here where R2R user Lasse proposed refrigerating the reagent (after opening) as a way to potentially prolong it's accuracy,,, which I've now started doing,,, but didn't know about the idea soon enough after opening my current bottle.

EDIT -- so I agree that your new water alkalinity water is lower than your tank alkalinity,,, but I question if both might actually be higher alkalinity than your checker is currently showing. (Just a thought,,, not statement of fact)

didn't know about he refrigeration - I guess that falls into the "do no harm" category, but would be good if that where backed by manufacturer

 

[DaJMasta]

You are asking me to dose the new badge of water with soda ash?

Yep, then you get your parameters where you want them before you mix it into the tank. Not different from adjusting the salt mix blend at the factory, and it can compensate if there was any alkalinity loss in storage (can drop slowly over time, especially with some).

What's more, even if your test kit has gone bad, if it at least reads consistently with itself, you can just buffer the fresh water until it reads 6.7dKH, and then add it to the tank for no loss in akalinity. It doesn't sound like a particularly bad reading to suggest the test is bad, but if you want to replace the kit you can still do a water change where you just make the numbers agree while you wait for the new test and buffering to some other level.

 

[Cali Reef Life]

Hana alk test kit broke 6 months after buying it lost 25% of my corals.