pH too high

[Formulator]

After years of struggling with low pH, it seems I’ve overcompensated and my pH is getting a bit too high for comfort. Yesterday it rose quite a bit after feeding and being severely nitrogen limited. Now it seems to be staying up there, topping out above 8.6!

I’m using NaOH as my Alk supplement. My Alk demand has increased with a lot of stoney coral growth this year and I’m wondering if I need to consider a different supplement for Alk or possibly remove my CO2 scrubber from my skimmer.

At what point does pH become dangerously high? Do I need to take action now or can it wait a day?

 

[anthonymckay]

In my Waterbox 230 I dose 6.5L of kalkwasser a day + use a co2 scrubber. My pH hits 8.6+ at the peak each day and haven't observed any issues.

 

[Miami Reef]

I recently added a CO2 scrubber and I’m using Sodium hydroxide for the alk.

My pH was at 8.5 last night. It would have been higher, but I closed my dosing pumps at that point. I get worried that one day I’ll have a precipitation mess.

I’m wondering if there’s a way to make my CO2 scrubber less effective without wasting or permanently degrading it.

Or I can switch to soda ash for the alk part.

This thread was made at the perfect time.

 

[Miami Reef]

Here’s another idea I pondered up:

My pH tends to reach 8.5 toward the end of the light cycle.

But when the light turns on, the pH is about 8.2ish.

So I’m going to set up my doser to add my 3 part during the hours the pH is lowest.


Once I finish my gallon of sodium hydroxide, I might switch to soda ash. We’ll see.

 

[dangles]

My pH is running about the same. I did a bunch of reading on R2R and I’m no longer worried about it. YMMV, DYOR etc etc

 

[WhatCouldGoWrong71]

I’m curious on the same topic.

 

[Miami Reef]

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.

 

[TangerineSpeedo]

Just throwing this out there... My PH probe needs to be cleaned an recalibrated. My Apex has crept up to 8.47 now, when in fact using other calibrated instruments it is around 8.3 ish.

 

[Miami Reef]

Just throwing this out there... My PH probe needs to be cleaned an recalibrated. My Apex has crept up to 8.47 now, when in fact using other calibrated instruments it is around 8.3 ish.

This is VERY true in my experience. When my probe is out of calibration, it shows much higher than reality.

When I was new at this, I was content with the readings. I was hitting 8.3 daily without my co2 scrubber and feeling on top of the world.

Then once I calibrated it, I was dumbfounded at the 7.9-8.0 reading. lol

Now I calibrate my probe monthly. I have a bulk collection of 7 and 10 solution packets.

 

[Randy Holmes-Farley]

I’m wondering if there’s a way to make my CO2 scrubber less effective without wasting or permanently degrading it.

Or I can switch to soda ash for the alk part.

This thread was made at the perfect time.

Meter just some of the air through it.

 

[Formulator]

Just throwing this out there... My PH probe needs to be cleaned an recalibrated. My Apex has crept up to 8.47 now, when in fact using other calibrated instruments it is around 8.3 ish.

Good suggestion, but I already checked and it is accurate.

 

[Formulator]

So I understand the precipitation issue, but what about animal health? Do we have a pH limit that is healthy for fish and coral (and inverts)?

 

[Formulator]

Here’s another idea I pondered up:

My pH tends to reach 8.5 toward the end of the light cycle.

But when the light turns on, the pH is about 8.2ish.

So I’m going to set up my doser to add my 3 part during the hours the pH is lowest.


Once I finish my gallon of sodium hydroxide, I might switch to soda ash. We’ll see.

I suppose that is an option, but I like the stability I get with constant dosing throughout the day. With my consumption, if I only dosed when pH was low, I think my daily Alk swing would be almost 1 dkh.

 

[Miami Reef]

I suppose that is an option, but I like the stability I get with constant dosing throughout the day. With my consumption, if I only dosed when pH was low, I think my daily Alk swing would be almost 1 dkh.

It’s 2 sides of the same coin. Is alk stability important? Is pH stability important? If we allow pH to fluctuate, is alk (bicarbonate) really stable?

Here’s a thought-provoking thread:

Alkalinity stability? pH stability? Are they even different?

It is currently the dogma of the reef aquarium hobby to say that alkalinity stability is very important for SPS corals, and that pH is not. Often, the very idea of someone trying to optimize pH is called “chasing numbers” as if that statement by itself shows it to be foolish. Since I have...

www.reef2reef.com

But I do agree that I prefer to dose around the clock. I’m going to figure out if there’s a way I can “meter” the air through the scrubber

 

[Randy Holmes-Farley]

So I understand the precipitation issue, but what about animal health? Do we have a pH limit that is healthy for fish and coral (and inverts)?

There’s no data suggesting a high end except that some macroalgae may grow more slowly as pH rises.

 

[Formulator]

There’s no data suggesting a high end except that some macroalgae may grow more slowly as pH rises.

There must be a high end somewhere, right? I mean surely a bath in hydroxide is going to kill most things. Are you just saying that within reason for a healthy tank, there is no upper limit?

 

[Randy Holmes-Farley]

There must be a high end somewhere, right? I mean surely a bath in hydroxide is going to kill most things. Are you just saying that within reason for a healthy tank, there is no upper limit?

Surely there is. The question is whether it is ever reached in a reef tank where many processes limit the pH rise, such as aeration and precipitation of calcium carbonate. We just don’t have evidence of problems with most organisms at attainable pH.

In reality, getting pH to 8.7 in a reef tank, except during emergency overdoses, is highly unusual, if it ever happens.

 

[Formulator]

Surely there is. The question is whether it is ever reached in a reef tank where many processes limit the pH rise, such as aeration and precipitation of calcium carbonate. We just don’t have evidence of problems with most organisms at attainable pH.

In reality, getting pH to 8.7 in a reef tank, except during emergency overdoses, is highly unusual, if it ever happens.

Well, I’m going to hit 8.7 tonight… Could I add some vinegar to keep it down?

 

[Miami Reef]

Do you want to carbon dose?

Just remove the scrubber from the skimmer. That will inject CO2 and lower pH — no carbon dosing needed.

 

[Randy Holmes-Farley]

That sounds better to me, unless you need to lower nitrate.