Alk rise?

[MizTanks]

Haven't changed anything aside from removing my internal skimmer and added a surface skimmer. Alk's been testing (redsea pro kit) at 8.4 for quit some time, dosing 15ml nightly of ESV 2 part. Ca's been steady at 425 dosing same amount daily. 12hrs apart.

Yesterday I did a wc with an sg of 1.027 testing today. A little higher then usual, Oops me! Tested my alk today and it's reading 10.1 and ca still the same at 425

Any ideas on why the rise? I'm not worried, just curious :)

[CalmSeasQuest]

Assuming you're using a higher Alk salt mix such as RC, your Alk increase likely resulted from your higher-salinity WC. You likely would experience an Alk increase with any significant WC% even if matched to tank salinity as your salt mix contains a greater then 8.4 Alk.

For reference, a 2.8 dKh increase in Alk only increases CA by 20ppm, so the increase is mostly evident on Alk readings.

[MizTanks]

Assuming you're using a higher Alk salt mix such as RC, your Alk increase likely resulted from your higher-salinity WC. You likely would experience an Alk increase with any significant WC% even if matched to tank salinity as your salt mix contains a greater then 8.4 Alk.

For reference, a 2.8 dKh increase in Alk only increases CA by 20ppm, so the increase is mostly evident on Alk readings.


Totally makes sense to me :) and is what I figured but wasn't totally sure. I'm still learning about how this chemistry stuff works lol

So usually my sg is 1.025 and alk is 8.4....raising my sg to 1.027 then raised my alk to 10.1 sound about right?

[CalmSeasQuest]

Totally makes sense to me :) and is what I figured but wasn't totally sure. I'm still learning about how this chemistry stuff works lol

So usually my sg is 1.025 and alk is 8.4....raising my sg to 1.027 then raised my alk to 10.1 sound about right?
The missing variables are what salt/Alk and and what % of water was changed - but yup, that's about right. ;)

[binford4000]

if your useing RC and opend a new batch it could be your salt also but raiseing your salinty higher will show a increase in alk for sure.

[MizTanks]

Using RC at 25% WC