pH too high

[Miami Reef]

You’ll also save $$ on CO2 media.

Pro tip: maintain alk around 7.0-7.5dKH. It will require less dosing to maintain, and the CO2 aeration effect will equilibrate to lower pH if the alk is lower — both will result in less pH, which is what you need.

 

[gbroadbridge]

Very high pH is a significant risk factor for precipitation. Once you start to have precipitation, the seed crystals will further encourage more precipitation. It will be a domino effect.

To remedy that, you’ll need to switch to sodium bicarbonate. It’s just a headache and not worth risking because then you’ll have to have the opposite result: low pH for a while.

In my opinion, 8.4 is the highest we should be striving for. Any higher, and it causes me to feel angst.

My tank has been running like this for ages.
Soda Ash dosing and CO2 scrubber on the skimmer intake.
Probe is calibrated at pH 7 and 10.
Confirmed with a standalone Milwaukee ph meter.

Doesn't seem to bother anything and I stopped worrying about it.

 

[Miami Reef]

My tank has been running like this for ages.
Soda Ash dosing and CO2 scrubber on the skimmer intake.
Probe is calibrated at pH 7 and 10.
Confirmed with a standalone Milwaukee ph meter.

Doesn't seem to bother anything and I stopped worrying about it.

How high is your alk?

 

[gbroadbridge]

How high is your alk?

Not particularly high ...

 

[Miami Reef]

Not particularly high ...

OK that’s good to know. Your numbers are about where mine are now (my pH goes as high as 8.5 at times). I haven’t had precipitations issues as of yet, but it does worry me when it gets high.

Thanks for the reassurance. Maybe it’s not so much of a risk as I once thought. Seems like a lot of people in this thread are pushing pH up.

 

[butterfield]

You could try alternating between dosing NaOH during the nighttime when pH tends to be lower and soda ash during the daytime when pH tends to be higher. Both could be calibrated to maintain alkalinity during their respective dosing times and pH theoretically would be more stable.

 

[Formulator]

Update - I lowered my target Alk to 9.0 from 9.5 and disconnected my CO2 scrubber. It seems to have been effective at bringing me down just a tad, which is what I wanted.

I’m not willing to cut my Alk back all the way to the 7’s as I’m striving for rapid growth right now after my tank reboot last year.

We will see tonight, but based on my low point this morning I expect to max out below 8.6 tonight.

 

[Miami Reef]

Update - I lowered my target Alk to 9.0 from 9.5 and disconnected my CO2 scrubber. It seems to have been effective at bringing me down just a tad, which is what I wanted.

I’m not willing to cut my Alk back all the way to the 7’s as I’m striving for rapid growth right now after my tank reboot last year.

We will see tonight, but based on my low point this morning I expect to max out below 8.6 tonight.

We have the same goals.

 

[scotty333]

Not particularly high ...

What are you using of reef factory to get that Ph graph?

 

[Formulator]

Update: So far it seems like I might have found a sweet spot, maxing out my pH at just a tad over 8.6 at the end of the photoperiod. To summarize for others in the future looking to do the same - I achieved a pH reduction of about 0.5 units by removing my CO2 scrubber and lowering my Alk target from 9.5 dKh to 9.0 dKh.

Again, striving for rapid growth I want to maximize pH for those benefits while ensuring I don’t have water clarity and equipment issues due to abiotic CaCO3 precipitation. I think this is that sweet spot based on the last 2 days and my tank’s appearance.