I want PH stability!!

[powdr_dayz]

Hello!

I have had a 72 Gallon system up and running for approximately 6 months and have always had difficulty maintaining my PH ~8.1 - 8.3 throughout a daily cycle.

First, I'd like to give some details about my system.

• CPR 194 Protein Skimmer

• Current USA CU1024 Lighting System (2 x 65W Dual Daylight, 2 X 65W Dual Actinic Blue). 12 Hour Day/Night Cycles

Parameters (measured this week)

• PH: 7.6 (Morning) - 8.4 (Night) (0.8 swing!!)
• Calcium: 460ppm
• Nitrite: 0ppm
• Ammonia: 0ppm
• Nitrates: 20ppm
• Magnesium: 1250ppm
• Carbonate Hardness: ~7dKh
• Specific Gravity: 1.022
• Temperature: 78C
• Phosphates: 0ppm

In my research, I found that there are three basic elements involved in PH stability: Calcium, Magnesium, and Alkalinity. I have just recently been dosing Magnesium (as it was low) in order to get it to the 1250ppm point. During this time, I was not using any dKh buffer or calcium supplement. should I continue to add Mg until I break the 1300ppm level? This was the recommendation from the LFS.

Does anyone else have some helpful insight/advice about this problem that I have been battling? Is a calcium reactor the best method for controlling PH?

Thanks.

[Fat Tony]

Your pH will vary throughout the day and night due to CO2 absorption from micro algae photosynthesis. It is a common and natural event. Unless your pH is dropping below the 7.80 you have nothing to be concerned with. pH swings throughout the day can actually have a good possitive effect on the inhabitants in your tank. It can make them hardier and more resilient to changes in water parameters.

[powdr_dayz]

In the mornings, I measure a PH of 7.6. Should I be alarmed?

[Fat Tony]

That's a little on the low side.. how are you measuring pH, with a properly calibrated probe or a test kit?

A calcium reactor would actually negatively affect your pH due to the CO2 entering the tank from the reactor. Kalkwasser drip would be a better method to control pH and running your skimmer intake outside would also help

[powdr_dayz]

I'm measuring it with an API High Range PH test kit.

By running the Skimmer Intake outside... do you mean the Air Intake?

[motorslave]

Ive heard of lower. Is the system by a window? Our homes become lower in oxygen when they are closed up. An open window and circulating fresh air in the house can have a great affect on Ph. I have heard of folks actually plumbing the air intake of their skimmer to the outside for this reason.
I also second what Tony said about a reasonable swing being good for the hardiness of the tank occupants. Stable is great but if something did happen in a tank to critters that weren't used to any change, it would be bad much quicker than if everyone was acclimated to some reasonable change.
Now with that, if you cant get a solid answer here soon ( that you like and woks for you) If you have a sump lighting it (no special light needed) opposite the tank lighting schedule will help stabilize the Ph a bit.
As for the Mag issue, I have found with my tank that it is much easier to adjust Alk and Ca when Mag is in line. Just don't get in a hurry and do one thing at a time for accurate test readings and better results.

[Fat Tony]

Originally Posted by powdr_dayz

I'm measuring it with an API High Range PH test kit.

By running the Skimmer Intake outside... do you mean the Air Intake?

yes, the air intake.. It will help bring some fresh O2 into a closed system that may be chock full of CO2 (your house)

[luther1200]

You might want to look into kalkwasser. It does a great job at raising pH. But it also raises Ca/Alk so you have to be careful with it. If you aren't familiar with it make sure you read up on it before dosing it. But don't get the wrong idea its not dangerous or anything but yoy could raise your pH to high if you dose it incorrectly.

[three90s&125sump]

I'm with the above statments about CO2 saturation (or bad tests) open a window from time to time and put a fan in it to bring the houses CO2 saturation back to normal. If you have anything restricting air flow to the water either remove it or make it so fresh air can get to it. This means open your cabinet doors so the sump can breathe. Also, at nornal atmospheric saturation of CO2 you must have an KH reading of at least 7. If you have more CO2 you need to have a higher KH. If your at 10DKH and you still have low pH then you definatly need to ventilate the house and I would also cite that as the cause of your late evening head aches if you have them.

HTH

[crvz]

Before doing anything, I would get a better means of measuring the pH. Test kits for pH are not accurate or precise. A recently calibrated quality probe is about the only thing to trust when it comes to measuring pH.

[three90s&125sump]

Originally Posted by crvz

Before doing anything, I would get a better means of measuring the pH. Test kits for pH are not accurate or precise. A recently calibrated quality probe is about the only thing to trust when it comes to measuring pH.

+1

I don't even test for pH right now I just keep ventilating the house from time to time.