New tank PH Issues

[ariellemermaid]

I’m posting in the new forum because I’m starting a new tank. This is my first large build with a sump and skimmer.

My RS XXL750 (“200g” total but closer to 130g of actual water) has been going for about 2 months. From day one until today the PH has been on the low side (7.6-7.7). I added a refugium on reverse schedule, however due to chaeto shortages I don’t have very much right now. I also went ahead and turned on the lights and added a bunch of cespitularia that was over growing the old DT. None of that made a dent.

Here’s what I’m looking at:

The peak you see is my overnight Alk dosing. It’s about 2:45 PM at the time of the photo.

I know the usual things…. Good agitation plus skimmer, fresh air, keeping the Alk in a good range, etc. The thing is I have a 20g coral tank in the same room (2 yrs old). All it has is an HOB filter and one small powerhead that doesn’t agitate the surface. That’s it. And the pH range is 7.85 to 8.05. Granted the Alk is higher at 10.62.

Given that this tank has a skimmer and great powerhead surface agitation I didn’t expect this. I have a bunch of corals I’m anxious to get into the tank but I’d like the pH to be in a better range first.

Is this because the tank is only 2 months old, because it doesn’t have all the corals the other tank has, or something else? Other than starting to dose kalk, I’m not sure what to do.

 

[homer1475]

My first question would be, have you verified the PH probe is working properly?

Meaning,
If you dunk it in a 10.0PH solution, does it read 10.0?

 

[ariellemermaid]

My first question would be, have you verified the PH probe is working properly?

Meaning,
If you dunk it in a 10.0PH solution, does it read 10.0?

I added the Apex either immediately or slightly after starting the tank, so within 2 months the probe was calibrated. I will say the first calibration didn’t work. But the second did (both calibration solutions read correctly after calibrating).

 

[homer1475]

And the pH range is 7.85 to 8.05. Granted the Alk is higher at 10.62.

This ^^

With higher alk, your driving out more co2.

Since this is the only difference between tanks, would be my first guess if the probe is reading properly.

Have you checked since you calibrated the probe? Apex probes are known for being wonky even right out of the box.

Tried a simple titration test?

 

[HuduVudu]

If I am really interested in a number I have at least two different ways to verify. For pH get a Hanna pH tester. I know people don't like those but it gives two ways to arrive at a number.

Second get a CO2 monitor. This to me is way more important than a pH probe. Most pH problems are from ambient CO2. Knowing what your CO2 is will either tell you the problem or elminate it from the list of possibilities.

Too many times I see people trying to solve CO2 problems with chemicals this will never work and it causes a lot of frustration and confusion.

I noticed that you said you are dosing alk. If you are dosing just one part of a two part you are going to have serious wierd problems. down the line. There is a reason it is called 2 part. You need both parts because you aren't just dosing calcium or alk you are also dosing sodium and chloride. You need both parts to provide the proper chemical balance.

 

[ariellemermaid]

This ^^

With higher alk, your driving out more co2.

Since this is the only difference between tanks, would be my first guess if the probe is reading properly.

Have you checked since you calibrated the probe? Apex probes are known for being wonky even right out of the box.

Tried a simple titration test?

Question answered I guess lol. Just calibrated my probes again and the new tank is reading 8.1 and the QT is reading 7.85. I’m pretty disappointed there was such a difference within just 2 months or less of calibrating. With the QT I had to calibrate like 4 times which is weird. Also weird is that I took a cup of new tank water and dropped my old calibrated QT probe in it; it read 7.9 when the QT was reading 8 (so fairly consistent with new calibrated DT probe). The new DT calibrated probe is reading 8.1 but the calibrated QT probe in the QT is now reading 7.85. I’m starting to think I shouldn’t hang my hat on any of these readings….

If I am really interested in a number I have at least two different ways to verify. For pH get a Hanna pH tester. I know people don't like those but it gives two ways to arrive at a number.

Second get a CO2 monitor. This to me is way more important than a pH probe. Most pH problems are from ambient CO2. Knowing what your CO2 is will either tell you the problem or elminate it from the list of possibilities.

Too many times I see people trying to solve CO2 problems with chemicals this will never work and it causes a lot of frustration and confusion.

I noticed that you said you are dosing alk. If you are dosing just one part of a two part you are going to have serious wierd problems. down the line. There is a reason it is called 2 part. You need both parts because you aren't just dosing calcium or alk you are also dosing sodium and chloride. You need both parts to provide the proper chemical balance.

Yeah I’m dosing both. To be honest I don’t fully understand the Alk and Ca consumption before even adding any corals but I needed to dose both to keep stable.

I’d like to have a different pH reading to check things against but I already have 2 probes with the Apex and calibration solutions. API pH test is basically just a rough estimate and not super helpful. As you said, chemically adjusting pH isn’t really a great solution so ultimately aside from adding outside air there isn’t much to do about pH and thus I’m not sure buying another pH probe would be a great use of resources…

 

[homer1475]

As you said, chemically adjusting pH isn’t really a great solution so ultimately aside from adding outside air there isn’t much to do about pH and thus I’m not sure buying another pH probe would be a great use of resources…

Pretty much my conclusion. If you want to chase maximum growth, then by all means chase that magical 8.3 dragon. I don't care about maximum growth, and I do not care to chase that dragon. While PH is something to keep note of(it can alert you to issues), I could care less what my PH is.

Honestly, if I didn't have an apex probe to tell me what my PH is, I would never check it, nor care what it was(PH is not an issue in marine environment with sand and rock, in a well ventilated house with nominal Co2 levels).

 

[ariellemermaid]

Pretty much my conclusion. If you want to chase maximum growth, then by all means chase that magical 8.3 dragon. I don't care about maximum growth, and I do not care to chase that dragon. While PH is something to keep note of(it can alert you to issues), I could care less what my PH is.

Honestly, if I didn't have an apex probe to tell me what my PH is, I would never check it, nor care what it was(PH is not an issue in marine environment with sand and rock, in a well ventilated house with nominal Co2 levels).

Yeah there’s definitely truth to this. My current (old) DT is a tank that’s only been good for zoa’s and softies, it’s killed everything else even when chemistry was perfect. Like a year ago I gave up on carefully controlling chemistry because I was planning on this upgrade. To this day the pH is around 8 by API but I do absolutely nothing to make it so. No dosing, no Alk or ca tests, just semi-regular W/C’s. I didn’t expect it would take this long to get the new tank going but yet the old DT is doing great. But, in the end it seems like my probe calibration was the issue.

 

[WVNed]

My pH was 7.8-8.0 and I installed an outside air line for my skimmer and it went to 8.0-8.2. It stayed there and I stopped bothering to test it for about 16 months. Then I did a tank upgrade again and got a Hydros that came with a pH probe.
it runs 8.1 to 8.3 now and I can just look to see what it is. Kind of nice.