High Alk Question

[Skmaiden]

Quick chemistry question I’m trying to figure out to help a friend but a bit stumped.

They claim to have: a

- 14dkh
- no dosing
- Red Sea Pro salt (12dkh), 1/3 water change per week
- softies only
- well water source with RODI
- not a new tank but probably not super established/stable either

Is a 14dkh (higher than freshly mixed salt) even possible? What would you recommend? I'm thinking a lower alk salt but as to why it’s high i'm not sure? Maybe high alk source water coupled with high alk salt and low demand? test error? other?

Thoughts? thanks


test error?

Thoughts?

 

[coralfishreef]

What test kit are they using?

 

[Skmaiden]

Hanna alk, plus a “test tube” kind, not sure

 

[Skmaiden]

Ive also asked about rodi tds and waiting kn a response

 

[Chris A.]

Have them go to a pet store to test the water to rule out bad tests.

 

[Doug H]

What is the salinity level? If the tank has high salinity from mixing too much or evaporation that could drive up the alk. I agree that they should probably change to the Red Sea blue bucket.

 

[Reefried]

I agree. Salinity is most likely high

 

[Skmaiden]

Salinity is 1.026. Could an inconsistent salinity increase the alk even if the current salinity is ok?

 

[Chris.sturgis]

If they are not dosing I would question the accuracy of their salinity reading.

 

[JohnK]

If they are not dosing I would question the accuracy of their salinity reading.

I was just about to post the same thought. How is SG being measured, and how confident that it's accurate?

My first question when I see test results that seem impossible is, "is there test error?"

Alk can't go up without a source. Could be an additive that has misleading descriptions and instructions (ie anything that raises PH, using baking soda for PH), source water high in alk, or what else?

Is your friend chasing PH in any way? That's the most common explanation for "unexplained" alk rise.

 

[Liam]

Do you have any man made rock in the tank, there have been reports of incorrectly cured during manufacture rock leaching and causing a rise in alk.

 

[Skmaiden]

I was just about to post the same thought. How is SG being measured, and how confident that it's accurate?

My first question when I see test results that seem impossible is, "is there test error?"

Alk can't go up without a source. Could be an additive that has misleading descriptions and instructions (ie anything that raises PH, using baking soda for PH), source water high in alk, or what else?

Is your friend chasing PH in any way? That's the most common explanation for "unexplained" alk rise.

Are you implying salinity may really be higher than the 1.026 measurement?

 

[JohnK]

Asking to rule it out. Measurement errors happen, and with SG in particular devices sometimes drift and or have other issues.
IF- by chance SG is elevated, then alk and everything else goes up as well. 8dkh goes up to 9 then 10 as salinity increases.

 

[Tankful]

A test at a fish store would be ideal

 

[Greg Hiller]

>Is a 14dkh (higher than freshly mixed salt) even possible? <

Yes, but it depends upon the pH and the calcium and magnesium levels. If the pH is too high with high alk then calcium carbonate and magnesium carbonate will precipitate directly out of the water and make the water milky (don't ask me how I know!!).