pH Stability

[kfries]

I have been having trouble getting my pH to remain stable. I can get it to settle for a few days, but then it wants to drop off. This has been going on longer than I realized as the pH sensor I was using was not working right and then died on me. I have purchased a Hanna pH tester and I added an Apex for pH and temp. I was able to get it to stay between 7.75 and 7.9 for about a week or two. I did a weekly water change on Friday and it is now running 7.67 and 7.79. The pH dropped pretty steeply after the water change. Any idea what is going on here? My kalk is running between 9.5 and 10. I have a 20 gallon AIO. I have been running kalk in my ATO. I was running about a little over 0.3125 tsp per gallon. I added a skimmer which is pulling a little extra water out so i reduced my kalk to 0.25 tsp per gallon. I added the skimmer to help with the pH and remove waste from the water. I have a hard time grasping all of the relationships between Alk, Calcium, Magnesium, pH and the other chemistry items. I do measure everything weekly. Calcium has been stable around 425-440. Mag is usually between 1350 and 1400. This last week it was at 1260. Phosphates run around 0.15-0.30ppm and nitrates are averaging around 8.0ppm.

 

[BigMonkeyBrain]

I have been having trouble getting my pH to remain stable. I can get it to settle for a few days, but then it wants to drop off. This has been going on longer than I realized as the pH sensor I was using was not working right and then died on me. I have purchased a Hanna pH tester and I added an Apex for pH and temp. I was able to get it to stay between 7.75 and 7.9 for about a week or two. I did a weekly water change on Friday and it is now running 7.67 and 7.79. The pH dropped pretty steeply after the water change. Any idea what is going on here? My kalk is running between 9.5 and 10. I have a 20 gallon AIO. I have been running kalk in my ATO. I was running about a little over 0.3125 tsp per gallon. I added a skimmer which is pulling a little extra water out so i reduced my kalk to 0.25 tsp per gallon. I added the skimmer to help with the pH and remove waste from the water. I have a hard time grasping all of the relationships between Alk, Calcium, Magnesium, pH and the other chemistry items. I do measure everything weekly. Calcium has been stable around 425-440. Mag is usually between 1350 and 1400. This last week it was at 1260. Phosphates run around 0.15-0.30ppm and nitrates are averaging around 8.0ppm.

So, Alk 9.5 - 10.0 dkh, Calcium holding steady @ 425 -440 ppm. You can't hold PH and Mag is falling. Have you added anything to the tank, like rock or sand ?

Sounds like a CO2 problem on the PH with steady ALK and Calcium. Mag usage ?

 

[kfries]

I did add one small piece of reef rubble that I mounted a coral to, but it was the size of a golf ball. What do you mean by a CO2 problem? I will test my mag again today. It had been holding pretty steady.

 

[BigMonkeyBrain]

I did add one small piece of reef rubble that I mounted a coral to, but it was the size of a golf ball. What do you mean by a CO2 problem? I will test my mag again today. It had been holding pretty steady.

Dry reef rubble can lower Mag. CO2 changes in the air will affect PH.

 

[kfries]

Dry reef rubble can lower Mag. CO2 changes in the air will affect PH.

How can I increase the pH and maintain a stable level with out adding products like pH + or others? I added the skimmer to try and combat the CO2. It is a small skimmer and there is no port for outside air intake. Its a 20 Gal AIO. The skimmer is a bubble magnus miniQ nano. There is not a lot of room for a bigger skimmer with extra features.

 

[Randy Holmes-Farley]

How can I increase the pH and maintain a stable level with out adding products like pH + or others? I added the skimmer to try and combat the CO2. It is a small skimmer and there is no port for outside air intake. Its a 20 Gal AIO. The skimmer is a bubble magnus miniQ nano. There is not a lot of room for a bigger skimmer with extra features.

There is NO chemical you can add to raise pH that is not an alk additive.

pH is determined ONLY by alkalinity and the CO2 level. Water changes never solve low pH issues.

If you want pH higher, you need to reduce the CO2 in the water, which is usually done by reducing the CO2 level in the air that the tank is aerated with, or adding alkalinity additives that consume CO2.

 

[Uncle99]

I have been having trouble getting my pH to remain stable. I can get it to settle for a few days, but then it wants to drop off. This has been going on longer than I realized as the pH sensor I was using was not working right and then died on me. I have purchased a Hanna pH tester and I added an Apex for pH and temp. I was able to get it to stay between 7.75 and 7.9 for about a week or two. I did a weekly water change on Friday and it is now running 7.67 and 7.79. The pH dropped pretty steeply after the water change. Any idea what is going on here? My kalk is running between 9.5 and 10. I have a 20 gallon AIO. I have been running kalk in my ATO. I was running about a little over 0.3125 tsp per gallon. I added a skimmer which is pulling a little extra water out so i reduced my kalk to 0.25 tsp per gallon. I added the skimmer to help with the pH and remove waste from the water. I have a hard time grasping all of the relationships between Alk, Calcium, Magnesium, pH and the other chemistry items. I do measure everything weekly. Calcium has been stable around 425-440. Mag is usually between 1350 and 1400. This last week it was at 1260. Phosphates run around 0.15-0.30ppm and nitrates are averaging around 8.0ppm.

I see also an 8 and some 7.8
Nothing wrong with that at all IMM.
PH will run 7.8 to 8.0 for most reefers.
With zero testing and adding nothing.

 

[BigMonkeyBrain]

How can I increase the pH and maintain a stable level with out adding products like pH + or others? I added the skimmer to try and combat the CO2. It is a small skimmer and there is no port for outside air intake. Its a 20 Gal AIO. The skimmer is a bubble magnus miniQ nano. There is not a lot of room for a bigger skimmer with extra features.

You are adding Kalk and your parameters are good, Alk high normal. The only other thing that I know that can affect PH is CO2.

A skimmer can add more CO2 to the tank if the surrounding air is high in CO2. CO2 is a heavy gas and settles close to the floor, if your skimmer is in a lower sump the skimmer can pull in more CO2.