Chicken/egg problem for Alk/Ca/PH?

[Randy Holmes-Farley]

So I installed the CO2 scrubber this afternoon and hit a new pH high of 8.24.

I've heard the CO2 scrubbers can be too effective...so I'm monitoring closely and will take it offline if it continues to climb.

Anyway, my pH average is still 8.15 as I've been between 8.06 and 8.22 over the last several days...

"too effective" may mean higher than your target, but I've never seen a low pH tank get to a pH too high using a scrubber alone.

 

[arking_mark]

"too effective" may mean higher than your target, but I've never seen a low pH tank get to a pH too high using a scrubber alone.

Good to hear. My pH continued to climb overnight to 8.29. I never thought I would see anything close to that considering I started at 7.8...

On a side note, I'm not a believer in Skimmers for effective filtration. I've been reading skimmate analysis studies.

However, it was a @Randy Holmes-Farley post that mentioned how effective skimmers are for tank aeration...and why I decided to try one again.

Skimmer + CO2 scrubber + Kalkwasser = great pH.

 

[arking_mark]

For those following along...the pH has seemed to really lock in at 8.29.

Prior to adding CO2 scrubber...red arrow indicates when scrubber was added. You can see I have been averaging a pH of 8.15.

Post scrubber, the pH really has locked in. We will see if this holds up with time...but I'm now averaging a pH of 8.28. This is actually the longest stretch my pH has been this steady!

 

[arking_mark]

pH seems to have settled in the range of 8.25 to 8.34 and I'm averaging 8.30. This is much better than I expected.

Alk may be seltling in as well...my bouncing between 8.8 and 9.6 seems to have settled closer to 8.9 and I think I'm seeing a more stable decline. I'm guessing my consumption is now more consistent and possibly increasing.

I'll see what the Alk does for the next several days...

 

[Randy Holmes-Farley]

Looks good!

 

[arking_mark]

"too effective" may mean higher than your target, but I've never seen a low pH tank get to a pH too high using a scrubber alone.

Are you sure? pH is getting to 8.36. Is a swing this large ok?

I actually built an air solenoid to automate cycling between CO2 scrubbed air to my CO2 heavy house air.

 

[arking_mark]

@Randy Holmes-Farley

It looks like my good pH may have unlocked Alk consumption.

I'll double check the numbers, but it does look like Alk is now being rapidly consumed.

In the last 7 days, Alk has gone from 9.5 to 8.1 despite dosing .25dKHish Kalk per day. My consumption looks like .45dkh per day.

If Hanna confirms and my Kalk strength is still high, I'll up the kalk dosing.

I'm not seeing any clear signs of coral growth...maybe coralline algae is starting to appear.

Any thoughts on the rapid decline?

 

[Randy Holmes-Farley]

Are you sure? pH is getting to 8.36. Is a swing this large ok?

I actually built an air solenoid to automate cycling between CO2 scrubbed air to my CO2 heavy house air.

My tank ran typically from pH 8.35 to 8.50 and was perfectly fine at that pH range.

You are not anywhere near high enough to be a problem.

 

[Randy Holmes-Farley]

Any thoughts on the rapid decline?

Normal for a pH increase, and it is never clear how much is due to increased organisms consumption, and how much is increased abiotic precipitation.

 

[arking_mark]

Normal for a pH increase, and it is never clear how much is due to increased organisms consumption, and how much is increased abiotic precipitation.

Thanks for the insight.

 

[arking_mark]

For those following along, I think I can more conclusively say that the increased pH unlocked my Alk consumption. The blue arrow indicates where I added a CO2 scrubber and have been averaging 8.30 pH since. My Alk has dropped from 9.6 to 7.7 despite increasing my Kalk drip. I'm back to .5dKH replacement and will be increasing it further as my Alk is still on a downward trend.

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[arking_mark]

Looks like things are working well. The increased pH unlocked Alk consumption which allowed me to increase Kalk dosing which increased pH and stability. Numbers are looking good and more importantly are stabilizing. pH seems to be locking in around 8.35ish and Alk at 7.8ish.

 

[arking_mark]

Normal for a pH increase, and it is never clear how much is due to increased organisms consumption, and how much is increased abiotic precipitation.

So I don't think I'm seeing much abiotic precipitation. Nothing in the powerheads, nothing on the heater, etc... My rocks are starting to turn brown/green which means they are maturing. I don't expect to get much Coraline algae as they like lower lighting...but I'm sure they will find places in the tank at some point. My Jellybean Chalice is definitely growing as is my WD. Everything else (not from the old tank) not so much.

 

[Randy Holmes-Farley]

So I don't think I'm seeing much abiotic precipitation. Nothing in the powerheads, nothing on the heater, etc... My rocks are starting to turn brown/green which means they are maturing. I don't expect to get much Coraline algae as they like lower lighting...but I'm sure they will find places in the tank at some point. My Jellybean Chalice is definitely growing as is my WD. Everything else (not from the old tank) not so much.

Nice. Just check the sand once in a while to be sure it isn't hardening.

 

[arking_mark]

Nice. Just check the sand once in a while to be sure it isn't hardening.

Sand seems good. I am finding what appears to be green coralline algae dots on my glass? Maybe still just brown diatoms...and just my wishful thinking.

dKH continues to nudge downward and has been at 7.5dKH since noon...bumped my Kalk dosing to 2ml/min or roughly .7dKH.

 

[arking_mark]

Very interesting...Alk continues to drop 7.3...despite bumping up Kalk. Gonna check calcium to see if anything funny is going on.

 

[arking_mark]

Very interesting...Alk continues to drop 7.3...despite bumping up Kalk. Gonna check calcium to see if anything funny is going on.

So calcium is at 462ppm and Hanna checker confirms 7.3dKH.

@Randy Holmes-Farley I'm not sure what's consuming the Alk. This is what I love about reefing... never-ending fun figuring it out.

So now I'm leaning towards abiotic precipitation. I just need to find where...

 

[arking_mark]

So calcium is at 462ppm and Hanna checker confirms 7.3dKH.

@Randy Holmes-Farley I'm not sure what's consuming the Alk. This is what I love about reefing... never-ending fun figuring it out.

So now I'm leaning towards abiotic precipitation. I just need to find where...

Here is a picture of my maturing rock...

 

[arking_mark]

One more thought for the night. This may be totally coincidental, but I did change salts a couple of weeks ago due to the unexpected jumps in Alk I was seeing in this tank and previously in my old tank...only thing in common was the salt.

 

[TheDragonsReef]

Good to hear. My pH continued to climb overnight to 8.29. I never thought I would see anything close to that considering I started at 7.8...

On a side note, I'm not a believer in Skimmers for effective filtration. I've been reading skimmate analysis studies.

However, it was a @Randy Holmes-Farley post that mentioned how effective skimmers are for tank aeration...and why I decided to try one again.

Skimmer + CO2 scrubber + Kalkwasser = great pH.

Curious as to what skimmate studies you're referring too? I'm always up for a good read