Ph swings and RTN

Yes as others have said, Your CA and ALK balance is out of wack.
I would allow your CA to drop and this will also bring your PH down.
The swing will stay the same but it's not that big a deal. I would contribute your RTN to the imbalance between your CA and ALK.

Check out the 3Reef calculators found HERE to help you balance

 

pH swings are normal. Corals uptake CO2 during the day (increases pH) and respirate at night (lower pH). You need to measure it at the same time daily (doesn't matter when). Calcium looks high, Alkalinity looks low, salinity looks low and Mag looks high. Try a 10-20% water change and see what happens.

Do you dose anything (Alk/Calc part A and B)?

 

I was adding kalk via my ATO water. That is it.

 

I mixing up enough water to do about a 12% water change. I'll do that later tonight and see if that helps.

 

Hi Cgarner

just be aware, as you are going to stop dosing the Kalk, you may need something to supplement Alkalinity

Kalk does both, in the correct proportions
you need either Arm and Hammer baking soda or any of the commercial part 2 (alkalinity supplements) these can be used to maintain Alk, which you do not want to drop below 7 really

Steve

 

I'm not stopping Alk totally. I just didn't want my calcium to continue to elevate so I removed it today until I can do a water change and get a handle on my Cal. I hope to hook it back up tomorrow or the next day.

Thanks for all the advice. I did a 10 gal water change and changed out my carbon and Phosphate. The phosphate reactor was really dirty and almost clogged with an orange detirus looking substance. I had it running for 5 weeks. I should have cleaned it a week ago but got busy with work and forgot.

 

My calcium dropped to 520ppm after a 10 gal water change. I'm making up some more water to do another 10 gal change tomorrow. I dropped my hana calcium checker and it died. I had to go buy another one. These checkers are fragile. They should come with a sticker.

I need to test my alkalinity as I still have my kalk offline.