High pH, Low Alkalinity

[bcarl77]

Hi Guys!

Recently moved from an apartment to a house and have developed a high pH problem (8.5). Historically it has always been low so I was running my skimmer through Co2 absorbing media. Before I moved (~1 month ago) I was dosing roughly 2 TSP/2.5gal of Kalk in my ATO. This would hold my alk right around 8 and pH around 8.3.

I noticed my zoanthids starting to look unhappy and start to close (all LPS are looking good). I measured my KH today and it was 5.8. For now I stopped running the skimmer and increased the Kalk in my ATO. Calcium came in a bit low at 400ppm. Any recommendations on how I can increase alkalinity without impacting my pH?

 

[Dr. Dendrostein]

Hi Guys!

Recently moved from an apartment to a house and have developed a high pH problem (8.5). Historically it has always been low so I was running my skimmer through Co2 absorbing media. Before I moved (~1 month ago) I was dosing roughly 2 TSP/2.5gal of Kalk in my ATO. This would hold my alk right around 8 and pH around 8.3.

I noticed my zoanthids starting to look unhappy and start to close (all LPS are looking good). I measured my KH today and it was 5.8. For now I stopped running the skimmer and increased the Kalk in my ATO. Calcium came in a bit low at 400ppm. Any recommendations on how I can increase alkalinity without impacting my pH?

They go hand and hand. Like to know what others think. Sorry

 

[bcarl77]

I know [emoji58]. Never thought I would be complaining about too high of a pH either.

 

[bcarl77]

Anyone?? pH is up to 8.65 at the moment...

 

[dougers31]

How are you testing??

 

[dougers31]

Hi Guys!

Recently moved from an apartment to a house and have developed a high pH problem (8.5). Historically it has always been low so I was running my skimmer through Co2 absorbing media. Before I moved (~1 month ago) I was dosing roughly 2 TSP/2.5gal of Kalk in my ATO. This would hold my alk right around 8 and pH around 8.3.

I noticed my zoanthids starting to look unhappy and start to close (all LPS are looking good). I measured my KH today and it was 5.8. For now I stopped running the skimmer and increased the Kalk in my ATO. Calcium came in a bit low at 400ppm. Any recommendations on how I can increase alkalinity without impacting my pH?

I believe you can use baking soda to raise alk without raising ph. Soda ash however will raise both.

 

[bcarl77]

I calibrated my apex pH probe twice and used a separate pH pen that I calibrated as well. That was my first reaction too....

 

[dougers31]

I calibrated my apex pH probe twice and used a separate pH pen that I calibrated as well. That was my first reaction too....

Could you alk test be off? Very strange numbers...

 

[bcarl77]

Measured 6.3 with Hanna checker and approximately 6.7 with Red Sea. At what point should I be concerned with the pH max?

 

[miniChou]

You can use two part to increase Alk/Cal levels. Although with a pH of 8.65 I would recommend taking your CO2 scrubber offline. 8.3 pH is usually what is desirable. As your pH comes down your Alk should come back up.

 

[jda]

Baking soda (sodium bicarbonate) will raise your alk and only have a momentary impact on pH. Washing Soda (sodium carbonate) will not impact the pH at all.

The kalk is why your pH is so high. Cut it back if you want to lower the pH.

 

[bcarl77]

Will dosing small amounts of white vinegar effect any other elements?

 

[jda]

Dosing vinegar will add organic carbon to the tank. With an influx of carbon, you will grow bacteria, sometimes at a large rate. If you grow them too fast, then they can use up all of the oxygen and kill your inhabitants. I would not recommend using organic carbon without a deliberate and long-term plan.

Turn your skimmer back on if you want to raise the pH. It can mix the co2 in the air into your water. Kalk drives the co2 out of the water which is why the pH rises.

 

[bcarl77]

pH bottomed out at 8.5ish last night. I don’t want to have it peak above 8.65 again.

I am away from the tank until Thursday and have limited control (fiancé) watching it. Should I kill the lights or unplug the ATO? She had some issues with the skimmer (crappy nano skimmer) starting. Could also have her grab an airstone. Not sure if I want to dose vinegar without watching it...

 

[nereefpat]

A weak organic acid (like vinegar) isn't a good way to control pH.

Aeration is good.

Baking soda is a great way to raise alk. It temporarily will lower pH until the CO2 is degassed.

I wouldn't worry about high pH unless you are seeing precipitation.

 

[steallife904]

Could your PH probe be bad? I had a high ph issue recently and turned out my probe needed replacing.

 

[Mical]

With #s like those I'd be suspect of salinity

 

[Coralfuture]

When my alk has dropped below 6.0 dkh many corals started to bleach and bail out. At 6.2-6.5 your coralline algae will bleach. Just as an indicator of how that alk test is reading out cuz low alk and the crazy high ph is surprising. I feel something is off in the tests somehow.

 

[bcarl77]

I had my fiancé triple check the reading again today with my pH pen which confirmed the high pH.

I am going to double check my salt level and verify it’s calibrated as well.

Turned off Kalk ATO and pH is not moving much hanging at 8.45...

 

[bcarl77]

Not sure how the Alk got so low in the first place when I am doing 40% twice a month water changes. And dosed only 2 TSP of kalk per 2.5gal in my ATO