Why is my alkalinity creeping up then falling down?

[Fisherman Joe]

Using the GHL IONdirector and dosing the Core7 Triton method.

My alkalinity is set to 8.5. The ion director always doses to try and achieve this.

Over a period of about a week, the KH will get up to 8.5 and stay there for a few days then drop to 8.0 overnight. Then usually lag a little and maybe move down to 7.7 over a few days before creeping up slowly back to 8.5 before falling again.

The IONDirector is set to add 50% more reagent from the standard (2ml per 100L) per day when the KH drops by 0.5.

So at 8.0KH the system is receiving 3.0ml per 100L.

All other parameters are within normal
Range. My pH is usually around 8.3 but can drop to 8.2 or sometimes 8.1.

 

[Frogspon]

Alkalinity swings while dosing sounds like an unstable PH issue.

 

[Rmckoy]

What’s your mag and cal ?

 

[Randy Holmes-Farley Verified Community Expert]

Sounds like a device problem, not a chemistry issue.

 

[jacalhou]

Sounds like a device problem, not a chemistry issue.

Wanted to bump off of this thread, as it was as close to my question as I could find after a quick search without starting a whole new thread. Randy, what is a normal or even acceptable Alk swing over the course of a day? I’m dosing silicates in an effort to outcompete dinos that I’ve been dealing with for quite some time, per the instructions on Mack’s Reef group on FB. I notice Alk creep up after dosing silicates such as water glass and/or Brightwell’s Spongexcel. My question is what’s too much of a swing in 24/hrs or so? I’ve been anywhere from 8.5 to 9.3 or so. I aim for 8.8 as my norm. More often than not it’ll go from say, 8.6 to 9.3.

Any expertise you can give would be greatly appreciated! Thanks Randy!