My Tunze nano pumps water from a reservoir into a Geo kalk reactor and then the water is forced up to my 20 gal JBJ. The total water volume is about 14 gal and so it's susceptible to big swings unfortunately. It's in a basement that is comfortable but I suspect has a lot of CO2 build up. Here is a chart from my Apex this week.
Each morning I have to dose two capfuls of alk which is the initial spike each day. (If I don't do this alk quickly drops to 6.5.) Then the kalk in the ATO and natural biological processes gradually increase the pH during the day. It stays pretty level during the day, then the lights go out and it starts diving. I'm aiming to keep it between 8.2 and 8.4. If I have an issue where the ATO doesn't run and then I fix it and it runs a lot, sometimes it will shoot up to 8.5. I even hit 8.6 one day. It hasn't wiped my tank out.
The only way I can even dream of keeping pH this elevated is because my skimmer is hooked up to a CO2 scrubber and recirculates the air from the foam coming up. As you can see, I had a major dip the last couple of days during the night. The pump quit working on the skimmer and that's what happens when the skimmer isn't running during the night. 7.8 ph by morning. I cleaned it and got it back up and running this morning which is the last peak on the right. The kalk gives it small bump ups during the night but the trend line will continue down fairly steep. I even run chaeto in the back on a reverse light schedule but I question if it's doing much at all with photosynthesis to help the pH drop during the night. It must not be enough.
Each morning I have to dose two capfuls of alk which is the initial spike each day. (If I don't do this alk quickly drops to 6.5.) Then the kalk in the ATO and natural biological processes gradually increase the pH during the day. It stays pretty level during the day, then the lights go out and it starts diving. I'm aiming to keep it between 8.2 and 8.4. If I have an issue where the ATO doesn't run and then I fix it and it runs a lot, sometimes it will shoot up to 8.5. I even hit 8.6 one day. It hasn't wiped my tank out.
The only way I can even dream of keeping pH this elevated is because my skimmer is hooked up to a CO2 scrubber and recirculates the air from the foam coming up. As you can see, I had a major dip the last couple of days during the night. The pump quit working on the skimmer and that's what happens when the skimmer isn't running during the night. 7.8 ph by morning. I cleaned it and got it back up and running this morning which is the last peak on the right. The kalk gives it small bump ups during the night but the trend line will continue down fairly steep. I even run chaeto in the back on a reverse light schedule but I question if it's doing much at all with photosynthesis to help the pH drop during the night. It must not be enough.