pH low. Should I try to raise it?

mkreef

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My pH is always on the low side and has been for several months. Should I try to raise it and if so, how?

My tank:
-57 gallon, mixed reef, moderate stocked with coral, smaller amount of live rock, 5 fish (tang and 4 chromis), 5 months old.
-pH swings from 7.55 to 7.95.
-recently calibrated pH apex probe.
-kH 8.5 to 7.5 (most recently 7.5 or slightly lower).
-1.0255 s.g. checked with multiple methods and constantly calibrated refractometer (using two sets of fluid).
-I have a gas water heater in the garage, gas range in kitchen, medium house and live in the city (if this matters).
-I use regular IO salt.
-If I vent the skimmer with fresh air from outside, pH raises maybe 0.1.

Thanks for any help!
Mike
 
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mkreef

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Screenshot_20210702-172008_APEX Fusion.jpg
 

fltt

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Following having the same problem.
 

Neil Fox

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Does introducing fresh air and surface agitation change the result? Do you run a fuge?
 

taricha

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-If I vent the skimmer with fresh air from outside, pH raises maybe 0.1.
I know you said you did the above already, but go ahead and pull a cup or bottle, and thoroughly aerate it with outdoor air for ~1hr as suggested below. (Randy has suggested this as well)

Does introducing fresh air and surface agitation change the result? Do you run a fuge?

If it moves pH to the mid-low 8s, then your measurements are correct and you just have high CO2. If it only moves pH up ~0.1 like you say, then one or some of your measurements is off.
 

Neil Fox

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You could also start using Kalk in your top off water. Old school, but works if all else fails.
 
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mkreef

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Does introducing fresh air and surface agitation change the result? Do you run a fuge?
I have tried using fresh air with the skimmer before but the line may have had a leak so inside air was being drawn into the system instead of outside. I currently have the skimmer out of my refugium as I was cleaning it two weeks ago and haven't added it back yet.

I just added two lines of fresh air pumping in from outside now that I started an hour ago. I started (then stopped) additional surface agitation with a fan. If inside CO2 is the issue, increased surface agitation would work against me, right?

I'll see how high it gets this evening. Hopefully 100% fresh air will help. Thank you for all of your responses.
 
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mkreef

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I've been pumping in outside air through a bubble stone disk in a refugium chamber for the past 2 days without any real effect on the pH. There was some initial jump the first night (<0.1 pH jump) but that has leveled off. The low yesterday was 7.62 and the high was still under 8.0.

I also recalibrated the pH probes on the Apex with fresh packets of standards yesterday just to make sure that didn't change things.

Are there any other things to look at before dosing something like kalkwasser? What is the best way to dose kalk, with a stirrer like the K1 by Avast?
 

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I've been pumping in outside air through a bubble stone disk in a refugium chamber for the past 2 days without any real effect on the pH. There was some initial jump the first night (<0.1 pH jump) but that has leveled off. The low yesterday was 7.62 and the high was still under 8.0.

I also recalibrated the pH probes on the Apex with fresh packets of standards yesterday just to make sure that didn't change things.

Are there any other things to look at before dosing something like kalkwasser? What is the best way to dose kalk, with a stirrer like the K1 by Avast?


You could do a recirculating co2 scrubber.
 

yoelf

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Had the same problem ended up buying a CO2 scrubber and that get me from 7.7-7.9 to 7.9-8.2
Corals are doing great just have to watch parameters after because my corals consume about 30% more cal and alk after adding it.
 

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arking_mark

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In the reef aquarium, your pH/Alk/CO2 are directly tied together.

Without going into the science or equations, your pH is determined by your CO2 levels and Alkalinity.

Randy has a great article on this:
www.reefedition.com
pH and the Reef Aquarium - REEFEDITION
by Randy Holmes-Farley For many aquarists, pH is not something that they have much experience with aside from their aquarium. For many, pH is almost a black box measurement: something to be considered, but whose physical meaning makes little sense to them. This article will Read more here...
www.reefedition.com

It's hard to control your indoor CO2 levels which are typically much higher then what you find outdoors. Just the number of people, pets, and other factors can greatly change this level from day to day.

So most pH problems are due to high CO2 house levels. You can test this with a cup aeration test. Aerate a cup of your tank water outside and measure pH and then aerate a cup of tank water next to your tank.

If your outdoor pH is higher, then you have higher CO2 levels in the house.

If your next to tank levels are higher, your tank needs more aeration.

Note that both of these can be true.

There are many ways to raise pH in your tank. However, many reefers are successful with pH between 7.8 and above.

A skimmer is essentially really good at aerating your tank and getting to the natural pH levels of your house CO2.

Here are several ways to raise your pH if your CO2 levels are higher in your home:
1. Crack open a window in tour tank room
2. Keep your Alk level very high 11-12ish
3. Using outdoor or CO2 scrubbed air for your skimmer
4. Use high-pH supplements (Kalkwasser or high-pH 2-part)
5. Reverse lighting schedule refugium
 

Snoopdog

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This image will show what high CO2 in a home can do, this is my tank from weeks ago till today. You can see where I installed my CO2 scrubber and the almost instantaneous difference. I had a very large amount of macro algae and also a refugium, both lit 24x7 and the PH would still not stay up. After I installed the CO2 scrubber I was allowed to remove most of the macro algae and just reverse light cycle the refugium and tank, this has helped remove the crazy PH swings also.

Untitled.jpg
 
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mkreef

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This image will show what high CO2 in a home can do, this is my tank from weeks ago till today. You can see where I installed my CO2 scrubber and the almost instantaneous difference.

Untitled.jpg
What scrubber/setup are you using? Are you scrubbing air coming from outside, or just scrubbing room air before the skimmer?
 

Snoopdog

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What scrubber/setup are you using? Are you scrubbing air coming from outside, or just scrubbing room air before the skimmer?

I have two of the BRS CO2 scrubber containers, both filled to the top. I have 3/8" hose going to the outside, my tank is against an exterior wall so that was the easy part. I do not really run a skimmer, I do not care for them so what I did instead of an air pump I took the venturi pump off an old skimmer and just ran the air to the venturi input. It works like a champ and no skimmer to clean.
 

Snoopdog

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I also want to add, do not underestimate how much CO2 is in your house, I had no idea why I have had low PH since doing reef tanks, 15 years now. I guess our houses here are prone to this because we have so much heat and humidity they need to not be drafty. 4-5 people locked in a house most of the days of the week and the size of your house does not make a huge difference, my house is not small by any means.
 

sdreef

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I've been pumping in outside air through a bubble stone disk in a refugium chamber for the past 2 days without any real effect on the pH. There was some initial jump the first night (<0.1 pH jump) but that has leveled off. The low yesterday was 7.62 and the high was still under 8.0.

I also recalibrated the pH probes on the Apex with fresh packets of standards yesterday just to make sure that didn't change things.

Are there any other things to look at before dosing something like kalkwasser? What is the best way to dose kalk, with a stirrer like the K1 by Avast?
I was just working on recalibrating my probes for my apex. When I was measuring the 7.0 pH fluid packet, I was getting 6.7. Despite recalibrating several times, resetting the pH probe, and other troubleshooting I was unable to get the probe correctly calibrated. I ended up replacing the probe altogether this evening and now the pH reading is accurate relative to the standards.

After recalibrating, is the probe measuring the standards correctly? I'm sure it is, but given my recent issue with a probe that had stopped functioning correctly, I figured it's worth mentioning.

I have been using a CO2 scrubber. It raises the pH in the system 0.2 - 0.3 and I change the media every few weeks. There is some expense involved with the media, but it does raise the pH.
 
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